[insane insecure]

I don't know what to do anymore! I've recently switched friends because my previous friends kind of replaced me and ignored me in conversations. One of my other friends stepped forward and took me into her group which I'm very thankful for. And its been better I've gone out more had a lot of fun but I'm extremely insecure. She asked me to go on vacation with her and her family but I know/feel I'm sort of a consolation prize because I heard her asking another girl to go with but she couldn't and then she said that she didn't want to go alone so if her mother didn't want to take her boyfriend with she would take me. And we've gotten a lot closer but it's buggin me because I feel that I'm a consolation prize and just there to keep her company and not because she wants me there. I know its stupid but this is only one of many such cases. And its not just with these friends its with everyone. I make myself crazy thinking about it and I get depressed and nausiated. I think my insecurity comes from the fact that I was overweight all my life and struggled to lose it. I've finally lost most of my weight but I'm not skinny I'm average. This also causes many insecurities like when people behind me start laughing I think they're laughing at me. I also almost pass out when I have to do speeches because I hate it when people stare at me. I hate mirrors and photos and I don't believe people when they tell me I look good/beautiful and I have ZERO luck with guys. I don't know what to do anymore I feel like I'm going to throw up because of the stress and I'm scared of being so depressed. Please help!