I understand much of what you are talking about. Especially the last year in college after I turned 21. My friends all wanted to go to bars and parties and stuff and that was all much too much for me. I often felt like a burden, buzzkill, lame, whatever you want to call it. Because I was having nearly constant migraines, I was avoiding drinking alcohol entirely - which meant that even nights in with friends were out. I still spent time with friends, of course, just not the "exciting college games" that involve drinking. It was hard and frustrating and really disappointing. I hear and understand that pain you're describing.
I loved a sentence in your post "I'm going through a season right now...". That's a great way to approach this. It's how I saw it too and it worked for me. Right now, your body and mind may be demanding certain things - rest, quiet, safety, etc. It will always need those things to some extent, but that doesn't have to limit you. There are many ways around those challenges.
The best for me for my sound sensory issues was to get decible reducing earplugs. I use Vibes, I know the brand Loop is also out there and I've been interested to try them too. They're really effective and make it so I can enjoy concerts and other loud events.
For most other sensory sensitivities, I find that being assertive and matter-of-fact about my needs helps the most. Instead of asking your friends at the bar "um, excuse me, could we maybe step a little to the left please?" Just say "this area is too crowded, I need to find somewhere with more space." + "Can you help me find a place? (Or) I'll be over there. (Or) Let's go find somewhere." If your friends are good people who value you, they will happily accommodate.
A lesson I've learned this past year is that if you need to experience something differently than most others in order to experience it at all, that's a very okay thing. Your ability to be present in the spaces you want to be in is valuable and worth the time, effort, and accommodation you need to exist there.
Try not to be too hard on yourself. You have needs that deserve to be met. You are not any less of a person or adult for having them.
Feel free to reach out if you want to talk. Good luck and have fun!