It could be something as simple as ectopic beats, likely pvcs if they hurt so badly but I agree with the previous poster. You should get checked out by a cardiologist if you are having severe chest pain and are feeling it difficult to function. Please keep us posted on how you are doing.
Well if the information you have provided is correct than you should really see a cardiologist as soon as possible. I'm not trying to scare you, but someone your age shouldn't have blood pressure that high unless there's some sort of blockage somewhere, or you have a family history. Either way medication should be controlling it a lot better. There's nothing we can do for you here. This need further investigation by a cardiologist. You need your heart, and kidneys checked, and maybe more to figure out what is causing this. If you're anywhere near a normal weight for your size than this shouldn't be happening.