I haven’t had sex. She just masturbated me and gave me a blow job with a condom.

I’m really worried. I’ve now got a stabbing pain in my penishead.

Being masturbated is not a risk, as long as the prostitute didn’t finger herself with the same hand first. Receiving a blow job while wearing a condom is not a risk either.
Your worries are unfounded. Perhaps your concerns are fuelled by feelings of shame or guilt. That can sometimes result in you experiencing symptoms.

If you stay worried, call (anonymously) an expert from the Aids STI Helpline on 0900 2042040 (10 cents a minute). You can also chat to a member of staff of the Aids STI Helpline via the chatroom on www.soatest.nl between 1.30 pm and 3.30 pm, Mondays to Thursdays.