Welcome to HCM.
The chances of getting through this way even if we suppose that this blood stain is from a HIV
positive individual, is very very remote. Even with a needle prick the 0.3-0.6% only. With insertive intercourse the probability is around 0.1-0.5% only. Just by touching the dry blood stain the chances of getting HIV disease is very negligible.
If this risk is high, by this time so many medical laboratory people. dental surgeons, obstetricians, emergency care providers and sanitary workers would have got this disease in large numbers. It is not so.
So nothing to worry and relax yourself.