If you are on birth control pills you can prevent your Visitor from arriving at an inopportune time by starting a new pack immediately after you finish up the active pills on the old one - so if you are on a 28-day pack that has the 7 day "neutral" pills at the end, you just start the new pack after day 21. I often use this trick to avoid having the Visitor arrive at inconvenient times. Saves on female products, too.
Melatonin works for some but if you want to use it you might want to experiment in advance -- I personally had a VERY negative reaction to it once (felt like I was on the verge of a psychotic break) and will never take it again. My DH has been taking it for awhile and it seemed to help at first, but doesn't anymore.
You might also want to try 5HTP. It can help with sleeping issues for some people (boosts serotonin).
On the public speaking thing, try being light/upfront about your jetlagged state at the beginning of the talk. It might help put yourself at ease and most audiences will be very sympathetic. And don't overprepare. When I was still in academia I learned that having a full paper in front of me made me a HORRIBLE public speaker. I would feel the pressure to read through it, and it was always too long, and so I was rushing, and it was just AWFUL. One time I actually hadn't finished the paper before the conference, so I spoke about my ideas from a pretty barebones outline, and it went great and I got all kinds of compliments. Who would have thought! I performed better without a paper than with one. After that, I just used the outline strategy, even if I had written the paper already. People always commented after on how natural and easy to engage with my presentations were after that. Of course all of this was back in the dark ages before everyone was using powerpoint, prezi, etc. But the same principle applies -- keep your presentation simple, focus on the core issues, and leave LOTS of time for discussion. The most interesting parts of most presentations are actually the discussions, anyway.
I've tried skipping the placebo pills before but since I did this just 3 months ago I didn't want to do it again too soon.
I have a total of about 200 slides and they've given me less time this time around to speak but want me to go a little slower so I'm already kindof at a disadvantage in that I'm jamming more material into less overall time.
I am totally like you in that 'less is more'...the more I've prepared in the past, the worst I've done. I usually excel when I practice 2-3 times and make concise talking points for only some of the slides. I won't be able to memorize all of the material; it's too much and too complex. Because of the audience I err on the side of being serious rather than light.....which can be dull...but I'm speaking to surgeons and they take themselves pretty seriously so...
With the Pill, I never do the 21/7 cycle. It's not natural for me (natural cycle is every 2-3 months) and I generally have no problems doing most cycles 5 weeks of active pills, 1 week off. Sometimes I can stretch it to 8 weeks, 1 week off (I judge by breakthrough bleeding). I hate that time of the month, so reducing how often is great for my quality of life. If you're worried about doing it too often, ask your GP next time you go.
Presenting:
I LOVE presenting, it's my favourite thing to do at work and I volunteer to present/run training sessions whenever I am able to. Before you think I'm just a freak of nature, in 2007 I was SO anxious about presenting and tried to avoid it whenever I could. Even informal presentations to small teams for 5 minutes on stuff I knew backwards freaked the crap out of me and I hated it, and avoided it where possible. So there is hope for you. But it does take time (a year or two) to gradually get over the anxiety, and I had kind and gentle coaching along the way from some of the more experienced people I worked with.
By the way, I'm always nervous the day before and I go through the "oh no, I can't do this, I'll make a fool of myself, what was I thinking to volunteer for this", even though I actually love doing the presentation.
The best thing ever that helped me was an annual conference that I used to present at every year (for a previous job). Most of the people there were senior engineers or managers and much older than me. I was much younger, one of only a handful of females (I was in a very male-dominated sector) and always felt slightly inadequate about feeling nervous each time. Then one year (I don't know why!), all the guys who got up to speak did this kind of confessional that they always (ALWAYS) get nervous before presenting. I think when the convenor confessed to this at the beginning (and he's a highly respected engineer, who MAKES HIS LIVING from presenting and running training sessions) of that conference, it suddenly made it ok for everyone to also say it. And now I feel so much better about my pre-presenting jitters. It's normal to have a moderate amount of anxiety about doing a presentation.
Concrete tips (I've spent a LOT of time thinking about how to give good presentations):
1) The general rule of thumb is 1 slide per minute (not including the time set aside for questions). So a 30 minute presentation with 5 minutes for questions should have 30 slides, including the intro/title slide and any acknowledgements at the end.
If you cannot get through all of the information that you need to, you can tell people something like "if you want more info, please seek me out in the breaks/lunch with any questions you might have - I'm happy to go into more detail on x, y, and z". Or if you have brochures or a research paper, bring copies with you to the conference and say something like "I have copies of the research paper/my company's brochures/catalogue with me if you want more info".
2) Slides shouldn't have too much text. If you have graphs or pictures, those are the best types of slides. Or a series of dot points, with a relevant picture (eg of the equipment that you're selling or something vaguely related).
3) The aim of presentations is to transmit the most important points into people's heads, not every piece of information you know on the topic. I figure if people remember 3-5 key pieces of information from my talk, I'm doing well. (and if they're interested in knowing more, they seek me out in the breaks)
4) I'm an introvert so I practise practise practise before a presentation. (my extravert colleague, on the other hand, loves to wing it. I really don't.) My DH can probably tell you how to use all of the obscure software that I've run training sessions on ;). I probably practise out loud maybe 10 or 12 times before presenting. The first couple of run-throughs are usually shit and I stumble over my words. Is there someone you can practise to? Even presenting to your pet dog or cat helps.
5) Slow deep breathing helps the anxiety. So does positive self-talk. "Even though I'm so nervous, my employer has confidence in me. I'll be fine on the day. It's normal to feel nervous. Everyone feels nervous before talking. I know my stuff better than anyone there" etc etc
Good luck! I have confidence in you. You will be fine :)