I have to agree that it is irrational anxious thinking if you fear that she sucked blood from a cut on her leg before kissing you . . . that's quite a stretch of the imagination. But EVEN if she did, it would not be a risk. HIV is inactivated by air and there are enzymes in saliva that break down the virus as well. So, this would never be a risk. The only ways that adults get HIV is from unprotected vaginal or anal sex or sharing IV drugs.
1. Odds of her giving you HIV is zero, zilch, nada!
2. No. You are not at risk. Therefore, you don't need PEP.
If you're always worried about irrational fear of HIV or other diseases, it won't be a bad idea to see a therapist.