Hey ReadySet,
I'm quite late to this thread but I'm glad I stumbled upon it.
I really related a lot to your OP. I was 29 just like you, had never had a major injury before, and was feeling in the prime of my life! Then boom, tore my ACL (and partial meniscus) while playing ultimate frisbee one day, in mid-2015.
Funny thing for me, it turns out my knees are super-stable. This meant that even after tearing my ACL, I could still walk and could still pass a Lachman Test. So instead of getting a proper diagnosis, my orthopedist just told me to take it easy, do some general strengthening, keep an eye on it. This continued for 4 months after the injury, I built up my strength again (particularly the quads and glute medius), and all the swelling from the initial injury went away. I thought I was good! Then I tried playing sports again, and within about 15 minutes my knee buckled ... so I knew my ortho had missed something. Finally got a proper diagnosis, which is when the ortho explained that I have abnormally stable knees. But yeah, it was time for surgery.
But anyway, I digress. I wanted to say, I think you made the right decision opting for surgery, and I was glad to see that you got a hamstring graft instead of patellar tendon. My research and some second-hand testimony indicated that a patellar graft can leave the quadriceps of the donor leg permanently atrophied and/or inhibited -- and evidently hamstring tendons are much better at regenerating fully.
For me though (as others have pointed out) the physical challenges of recovery were nothing compared to the mental battlefield. I was "crushed" as you said AFTER my surgery, because I wasn't mentally prepared to be cut off from all the physical activity that I loved, not to mention halfway out-of-my-mind due to narcotics in the first 1-2 weeks, not to mention being largely unable to drive and see friends. Being someone who craves personal contact (and most of us do, in some form) I was pretty starved of mental nourishment for the first 4-6 weeks after surgery.
However, as others noted, I was able to find a good PT who knew her stuff, and I focused all my spare energies on knocking out those reps every day. With some momentum growing due to the gains from PT, I got to experience something that I still find somewhat sacred -- recovering your strength is a little bit like growing younger from some ripe old age, e.g. Benjamin Button-style. I remember the first day that I was officially cleared to walk without crutches -- I found a neighborhood park, brought some alpine trekking poles as canes, and ambled around the track at a speed of probably 0.5 mph. And it felt like absolute magic, because I had spent the past 3 weeks bound to crutches.
And of course, with every new milestone after that -- being able to do real strength training again, being cleared for running, being cleared for cutting and turning -- you get to re-appreciate the wonder of having a working body that can transport you to physical enjoyment.
I suppose, by now, you've gotten to experience a lot of this, given that your surgery was already 2 months ago.
Hope it's been good! I'll get off my lackadaisical soapbox.
As for long-term prognosis though, I did want to touch on that. I related strongly to your feelings of being "crushed" and wondering if your future held any of the same kinds of joys as your past. Well, my advice is to keep focusing on those PT exercises long term, and do any kind of extra credit you can for your body. Be more aware and 'woke' to the state of your joints. Follow some bloggers or YouTubers who give tutorials on mobility, foundational strength, and flexibility. Especially watch out for the damage that working a desk job can do on you (I'm assuming most of us have desk jobs) and take active steps to compensate by lengthening your quads and hip flexors, working on hip extension, thoracic extension, continue strengthening hamstrings, and so on.
^^ And in the meantime, appreciate how much you're going to be able to still enjoy!
As a parting encouragement: today I am about 20 months post-surgery, and I'm probably in the best shape of my life. I play ultimate frisbee regularly and I am one of the fast people on the field -- sprinting, cutting, jumping, etc. I still have to pay attention to my knee, but when I've done my homework (e.g. exercises above) I can use the knee as though I'm still 20 years old.
Hope you're doing well! Feel free to reach out if you wanna discuss your recovery any further.