Can oral sex give you any infections or disease ?

Yes: Yes several std can be transmitted through oral sex. Like syphilis , gonorrhea, chlamydia and certain extent hpv. There are chances of hsv and if ulcer with blood contamination than HIV too.

Of course, STIs: Gonorrhea, genital herpes, syphilis, HIV and chlamydia just to name a few. If concerned, see your doctor ASAP for evaluation and tests.