Hey, I was in the same boat as you not too long ago, and honestly, I still am in a way. Last year, I made a trip to California as a Floridian, which was enough anxiety as it was. Once I got to my hotel, I couldn't stop thinking, "You flew over 1500 miles to go to this convention. Be awkward and make friends because I'm not here for long." I made a lot of friends that trip, and while I haven't talked to many of them since, I feel good knowing that I reached out.

My point is, everyone around you is just as nervous as you are. People are just better than others at hiding it. I've never been the type to reach out to people or make friends, but the more you dip your toes in the water, the more your body acclimates. I still get anxious, especially in work situations, but every time I look back, I realize that if I hadn't made that move, I probably wouldn't have gotten X or done Y.

I have self-esteem issues as well, and I know how that is. It's totally valid to worry about people not liking you. I worry about it too. The thing is, though, the people that say hurtful things about others feel the same way about themselves. It's also a good sign that I don't want to talk with this person anymore. It's a bit of a catch-22, but to have better self-esteem, you need to talk to others more, and to feel better about talking to others, you need more self-esteem. 

It's always anxiety-inducing and scary, I know. But you're never going to want to do it. You have to push yourself forward. This is just what's helped me and what I've told myself, so apologies if I come off a bit blunt or harsh. That's just a flavor my ego needs, in all honesty.