Insecure about my body. Advice?

Before I got pregnant I was around 94 lbs. I've always been very tiny so I've never been particularly in love with my body. I've always felt like I have a child's body. Well, after I gave birth I shrunk back down to 91 lbs. I pumped for my little preemie for 2 months and I hate my boobs now. They used to be a perky A cup but now they're smaller and sort of droopy. I hate them. I feel so insecure about my body and I don't know what to do. My body looks like I haven't even gone through puberty yet! I'm flat chested, I have no hips, and my butt is flat. My boyfriend of course loves my body but I don't... I don't know what to do. Any tips? This is my body pre pregnancy.