Pain in chest under left breast, Randomly...?

So I've been having chest pain for a long time now. I think it started when I was about eleven, with stomach pain and when i went to see a doctor they had told me that it was because of constipation because my bowels are messed up. i don't 'go' as much as i should, maybe a couple times a week...so the doctor put me on miralax and it kinda got better but then i started to get pain in my left side and/ or chest randomly when i was about fourteen and i wouldn't be able to really move without the pain worsening and i would have to be crouched or leaned over for it to kinda go away on it's own. it happened like when i would walk or eat fast food, and when it happened it would be hard to breathe, i would gasp for air. so when i went to the doctor they told me it was because of acid reflux issues and they put me on medication that i would take whenever this ooccurred but it didn't really help...but kinda stopped happening after i went on a special diet, you know like stopped eating fast food, fried greasy spicy, things that would cause acid reflux. but after a while i started to eat whatever and i was fine. like maybe another couple of years later it started with some mild pain under my left breast every once and a while...sometimes just when sitting and the same before, i wouldn't be able to move or take any deep breaths without the pain worsening and it go away unless it stayed kinda leaning with my hands over my chest, very still and it would gradually go away. But more recently it's been happening EVERYDAY, and it's like this gripping tight pain and it feels like my insides are just breaking. the other night when i was asleep i really thought i was dreaming because it hurt so bad. the pain just came out of nowhere and i had to hold on to myself in like a fetal position for it go away but anytime i moved it would come shooting back and i was in AGONY, and somehow after maybe 45 minutes or so , maybe because i was in and out of a dazed sleep when this was going on, it stopped when just laid on my right side and didn't move. on other days it happens when im lying down, or if im excising especially. basically it can happen when i do anything. don't drink or smoke or am on any medication. anything helps, would see a doctor but really tight on money right now. so looking for info online. im 18 yr. old female i still have constipation if that could be it....