Insecure but horny?????? Idk

 I'm 19 by the way!  o I'm a really insecure person. I had sex with one guy. We dated for 2 years. We've broken up awhile ago. But I'm not really in shape. I'm kinda chunky & I'm so self conscious about it. Not to mention one boob is soo much smaller then the other. I know everyone says oh that's normal guys don't notice that, well I do, to me it's worse than my weight but i can't do any thigh about it... Anyway, I want to persue a new guy but I'm really shy and awkward, he wants me on top and this is just for the making out, which I've done millions of times but he wants me on top which makes me insecure and I'm just really insecure but i know I have to like face my fears. I'm just afraid of being heavy and jiggly. The image I give myself makes myself sound so much bigger than I am, I'm not huge but it's just an insecurity thing. Sorry this is so long..