Did I just overreact?

I recently started dating again and I don't want to mess it up.. My last relationship was 3years long but my ex got to a point were he flipped on anything I did ether good or bad which I think made me close up in a way if that makes any sense? Anyway my current boyfriend is completely different but is always asking me to open up more to him or let him know what's wrong. I don't feel too comfortable putting my feeling out there but I've bin trying and I guess I can say I've gotten better. Now I felt comfortable sharing something with him it was nothing big but (I started the pill and my hair has bin falling a lot but I'm not so sure it's because of that) he gave me a smart ass answer that literally brought my whole mood down and just made me feel so dumb. I'm not sure if I am just over reacting since my last boyfriend made feel this way or.? Any advice?