I have chest tightness after a couple of minutes of exercise along with shortness of breath. Sometimes it goes away and sometimes it stays. Heart?

Quite possibly! This could be something quite benign (like deconditioning) or quite life-threatening (like angina). Since we can't tell on the internet, seek out a primary care provider who can listen to you and exam you and give you the best info on what, if anything, to do next! i hope it's nothing serious!