It appears to me from your response to Ed34 that you are fishing for someone to validate that you have cardiac issues.
If you remain extremely worried, I'd request a cardiac stress test and/or an Echocardiogram. If insurance won't cover it, it probably would give you some comfort to pay for the test by working a second job. That said, there was a doctor on this board about fifteen years ago that warned people about insisting on unnecessary tests, as almost everyone has some little tic or tac with their heart and you might center on it.
Regarding the HIV anxiety, I think I'd trust blood tests from a chemist instead of blowing up used condoms to check for leaks.
Ed34 gave you excellent advice, hope you heed it.
I think you have answered your own question, you are too anxious and stressed out. You either require medication to help with this, or councelling or both. You have a condition which, if not under control, will have you inventing dark roads in the end. All this stress is hitting your body, it isn't designed to handle such stress levels. Everyone who has heart disease has been there to some degree, including me. I just thought "well everyone on this planet dies at some time, even the best Doctors. We have no way to fight it and so I will just live each day as it comes and enjoy it". If you get your mind to calm down, your body will be allowed to relax, and you will start to feel much better. Personally I think it's a psychological issue you have, not a physical one.
That really didnt answer my questions at all
Yes, you should be concerned about heart disease, everyone on the planet should. However, being concerned doesn't mean you have it obviously. At your age, I very much doubt it. Secondary smoking has a lot of scare mongering attached and I don't take much notice. My parent both smoked, and my 2 older brothers have no disease and I do. Stress will bring about heart disease far quicker and so will a bad diet.