It is possible to get oral hsv2, but it's rare. In the 20+ years that I've been working in this field, and 10+ years on this site, I think I can remember 2 cases of it here and they self-reported. Terri Warren, one of the world's leading experts on herpes and a clinician, says she's never seen anyone get it from oral sex.
https://westoverheights.com/forum/question/more-panic/
Obviously, it does happen, because we have shedding data on it. It's just really rare.
HSV 2 genital 15-30% of days evaluated
HSV 1 genital 3-5% of days evaluated
HSV 1 oral 25% of days evaluated
HSV 2 oral 1% of days evaluated
If it does happen, it almost always only causes one outbreak ever, and never transmits.
Please don't waste any more time fearing something so unlikely to happen.
Listen, no one wants herpes. No one wants an STD. But you can still enjoy sex and protect yourself. Have you ever been tested for herpes? Find out if you have either type. If you do, you can't get that type again. You may have hsv1 orally, and that means you can't get it genitally. If you don't, talk to your partners, and get tested before you have sex.
The safer sex conversation should be one that you have before sex. It freaks you out - which is okay - so take some control over it. Ask for test results. Any decent partner is going to want to protect you, and won't find this unreasonable. Your partner should want to know about your STD status, too. You don't need to get into a detailed sex history, which often causes discomfort, and doesn't matter. You just need to know their STD status. Offer to go together to test.
Maybe you're a person who only has sex in relationships - that's okay. So am I. Maybe you can have casual sex - also totally okay. You just need to be able to figure out the balance with your concerns about STDs.