FWIW, I think it's great that you like your area and want to stay there and that your house is a really good financial option given local prices. The point of FIRE isn't just to become FI as fast as possible -- it is to become FI living the life that you want to live. So if you are clear that staying in the area is a priority, that helps set the parameters your working in. I mean, sure, you can always sell and be FIRE somewhere else, but what's the point if doing that would be living someone else's dream life instead of yours? It's also great that you've managed to stick to such low non-housing expenses in a HCOL area. Basically, you have your priorities straight, and you have frugality skills to optimize whatever you end up doing. You are completely set up for success regardless of what you choose now.
So with all that going on for you, you're not happy in your current job. You have multiple pathways available, and a huge amount of FU money to do whatever you want with those paths. Your current job is not satisfying. OK, you need some job, but you don't need this job. Would you rather find another comparable job that you bust it at for another couple of years, until you know you can quit forever if you want? Would you rather take a BaristaFIRE job for maybe 5-10 years for your 'stache to grow to the amount you need to quit permanently? Or would you rather quit entirely and try consulting? Which sounds most appealing to you? Investigate those options, figure out what best suits your goals, skills, and personality.
FWIW, I would not recommend part-time at your current job. Part-time works well when you enjoy the job but just don't want to dedicate so much of your life energy to it. I've been part-time for years and cannot imagine going back to full-time (I'm also FI, so it's great knowing that I never have to!). But if your job itself is annoying and frustrating, just doing less of it will not solve those problems; you'll still be annoyed and frustrated by those same things, and you'll still resent taking time away from your life to deal with those annoying and frustrating things. Unless you have a serious personal need to be part-time right now, you will very likely be happier if focusing on finding a different role that satisfies those itches that the current job isn't, vs. seeing if your life is better if you can just spend less time doing annoying things.
As with most things in life, you get what you settle for. The work you have put in so far to develop your skills, save a shit-ton of money, and build those frugality muscles means you don't have to settle for jack shit. So don't. Go after what you want. You may not ultimately get exactly what you want -- but you absolutely won't if you don't at least try for it.