I have the same problem!
I also used to get bad problems with my stomach when I met people so I always had to go home early and was scared to eat with others or meet them at all.
The only thing I've kinda learned to do is always ask my friends if they're feeling okay and basically asking for reassurance. Making them clear about my situation helped me a lot!
With strangers it's a different story though.
Only thing that sometimes prevents it from getting worse is knowing and telling yourself that your thoughts are unrealistic and if people hated you they wouldn't want to spend time.
I know it's hard to live with anxiety, just know you're not alone and people, especially your friends, will always listen to what you have to say!