Welcome to HCM
We understand your concerns
From the long description you gave it is very clear as day light that you are worrying un necessarily. First of all there is not a remote chance that you can have HIV / AIDS or cancer or any other STDs. Secondly every diseases has its own treatment and cure method.
You should not commit suicide
simply because you don't have any problem which can be cured by suicide. In fact you don't have any problem at all except some anxieties.Masturbation
using other methods as mentioned - Ask anyone, everyone does it, but moderately. Everyone searches for alternative methos of pleasure. Masturbation is not sin or disease. Men and women does it for ages. Problems due to masturbation comes only to 2% of population and that is due to un hygene.
Talk to your psychiatrist
and believe him.. You go to any doctor and they will also advice you to do so. You need sex and behavioral counseling
from a psychologist
. I can help you if you desire so.
Wish you speedy recovery.