not sure why i wake up sweating and breathing really hard

Ok, so I have been better now but almost all the time Im so irritable and people bother me. I usually avoid public situations,I just feel so much better at home. Im 15,and I just feel bad when I lash out at people,but its like a natural reaction.I do have trust issues and was bullied for a while.I can forgive but never forget.I dont talk to those people anymore ,now being in highschool I barely see them since they arent in my classes. Sometimes my friend make jokes about my moods, either calling them "emo" or "bi-polar", and I know they aren't serious but it gets tiring hearing the same jokes over and over.
I sometimes wake up sweating and breathing really hard, or I feel like my heart is going to jump out of my chest.Lately I have been getting chest pains that come and go, but they arent like unbearable.Like a little prick. When I try to sleep I breathe really fast without knowing it and when I try to take deep breaths and calm the speed of it, it doesnt work that much.
I went to the doctor for blood tests last summer and they found nothing wrong,is it just stress?
I dont know honestly, opinions? (please no mean comments :/ )