Your heart is not supposed to be racing, it is called tachycardia
, if you had seen a cardiologist and he checked you and found no problem, it may be panick attacks.
Based on what your social/economic situation I would go with anxiety
. Symptoms include, rapid heart beat, sweating, feeling as if you cannot breathe, impending feeling of doom. You would not have pain with this.
I would not play around with this, go to Emergency Room if it happens again, tell them you also have chest pain
, they will actually start the Medicaid process for you if you get admitted, or will offer you Charity Care to pay the bill, often with Charity Care they help you to file for Medicaid as well.
You do have a lot of medical problems, it probably would be good for you to go and tell them you are not leaving until someone figures out what is going on.