HIV cannot be transmitted through skin, regardless of skin tags, warts, etc. Your only issue is paranoia as a result of having sex with a sex worker.
What about the risks involvEd with masturbating on to her vagina and any kind of splash back? Also what if I already had the herpes virus, are the risks high with what happened?
Masturbating is not a risk and since you did not have an exposure it doesn't matter if you have herpes. There is only a risk sexually if there is penetration of a penis into a vagina or anus. HIV infection happens INSIDE the body.