Ha ha, I do actually sometimes get paranoid about STDs even though I know I've never had one and that, unless my boyfriend is sleeping around unbeknownst to me, I'm unlikely to get one. But then I've always been a bit paranoid, I remember when I was young I used to worry that I was pregnant before I had even had sex! (Yes, I am weird).
However, I'm not as paranoid as you. Book yourself in for a test, they really are nothing to worry about, and stop this, 'I don't want to die' business', it's ridivulous to get so het up about something so unlikely. Please just put yourself out of your misery by getting tested, I have no doubt that it will confirm that you are, indeed, not dying.