dont know whats wrong with me

Whenever I meet ANYONE, whether that be in person or online, I can easily start or keep a conversation going but once we start building any type of connection through mutual interests or just the fact that we get along for some reason I start becoming distant and avoidant. I dont understand why my mind does this but I feel like if I get attached then my whole mood will depend on how that person interacts with me, if theyre dry or not having a good day then itll ruin my day even if I was happy. 

So people start insulting me, usually but I always make excuses to leave and disappear. Its actually crazy why my mind thinks this is totally okay.