I know this is a bit 'out there' but please don't dismiss it. Are you doing any regular, sustained, intense, cardio exercise? Like running, swimming, cycling? If so, are you doing it regularly?
Cardio exercise will make a huge difference to your appetite, fitness, sleep & amazingly lifts your mood too.
I know putting on swimmers or sport or bike gear is not what you want to hear about.
I too never wanted to ever be seen in public in swimmers or do cardio exercise. Oh my God! My body ugh. But after much procrastination I did. I could barely swim so I watched countless YT on swimming & how to do it. It gave me the motiv to go to the pool. I didn't go with anyone or tell anyone. Just on my own & straight in the water and slowly started. No overthinking it.
I made a promise to myself that I would go every 2nd day for 6 wks - regardless of how I felt about it.
After a while I was going daily.
A nod here and a smile there to other swimmers but no big talks. So I liked that! But I didn't feel alone either.
Then I decided to do Tai Chi - yeah I know - sounds tame but very difficult btw. Making my body DO something started to feel so good I am now sort of addicted.
I discovered a tool to feeling good on my own.
Are you doing any sport? Can you try for 6 wks? I read that you don't see benefits for about six weeks. I felt benefits after 1 wk. kept going & then I started to need to do it.
If you're starting from scratch go slowly. Technique over speed. Write down your goals & progress.
For me, 50 m. pool, 50 laps. My first swim I did one lap & barely, on wobbly legs, got to the change room.
After 6 mths I bought swim earphones to enjoy my 50 laps more & I do.
Sustained cardio is a tool. When your body feels good it tells your brain to feel good. It isn't magic but it does feel like it. You must make it a habit though. A good habit. Habits just take repetition to make.
Aside from cardio please consider doing something like boxing, gym, self-defence where you do classes as well. Go, listen & do. If you meet someone friendly that's a bonus but that's not the primary reason you are doing it.
The idea is to find a way to feel good about yourself not wait to hear it from someone else & doing an activity where you have goals.
Take the stress off yourself regarding social situations. Do things you like & possibly meet people who like doing the same thing? Lots of possibilities there!
Let me know how you go hey?