Trying to figure out whats wrong with me....?

im 17yrs old and ive never been able to get to sleep well or stay asleep. i have been known for depression and suicidal behavior but i got help and i life a happy healthy life. recently ive been waking up with this feeling in my chest i dont now how to describe it but in best words i can is that feeling when youve been scared about something but when you find out nothings wrong and you get that feeling in your chest and your breathing is slow. it kinda feels like somethings pressing down on my chest but it doesnt hurt it feels fine please help?