health anxiety?

[size=10][font=georgia]basically, i've been convinced that i have some kind of deadly affliction for about two months now. every time i'm able to convince myself that i don't have whatever i think i have, another thing will come in to take its place. for example, it started out as a heart attack (chest pain), changed to a stroke after about a week (headaches, neck stiffness), then cancer (lung: numbness in my back, brain: more headaches, throat: sore throat), then dvt/pe (i talked to a friend on skype for 6-8 hours straight without standing, and my leg hurt afterwards for about a week), now its back to cancer (specifically brain/lung bc headaches/chest pain/weird back numbness). i've been to a doctor before (hell, my mom's a doctor) but i just can't seem to believe that nothing is wrong with me? i've even had my blood taken to assure that nothing is wrong (and i got perfect results), but i still can't help but worry (and it doesn't help that i typically feel short of breath when i'm anxious, which is a symptom of a lot of the above things...) i just always end up googling symptoms (which is an AWFUL thing to do, i know) and reading all of these stories about people who were told nothing was wrong with them by their doctors, but they actually had some type of cancer, and they scare the shit out of me. i just don't know how to stop this. i figured it would go away after a few weeks when it started, but it just hasn't gone, and i hate telling people about it, because i feel like it makes me an attention seeker, in a way? like, i know how horrible these conditions are, and i'm convinced i have them and that my life is horrible, but there are people who actually have them and have much worse lives than me and ugh... i just don't know what to do :/