Welcome to the life of a hypochondriac :p It seems like everyday is a "new" symptom or disease. Alot of it is stress/anxiety. Anxiety is a cruel thing, and it sits in your subconcious ALL DAY and will wait for something to happen- literally ANY stressful situation- even locking your keys in your house- and suddenly you feel like you are having a heart attack. I too have shared many a trips to the ER and even had to switch doctors because my regular family doctor started to argue I was just crazy!
When you stress out, your hold body tenses- that could be what is causing the pains in your chest/arms- muscles that are becoming too tired of constant contraction. Also, if you can afford it, try to see a chiropractor. I was getting lots of pains/stomach problems and it turns out, I had a disk pressing on my T6- this is where the nerve is connected to your stomach, gall bladder, intestines, etc. My back was out- and it was making me sick! So simple! I am hoping that this can find you some relief and just know you are not alone.
All the best from Canada, eh!