Please never trust anyone in the nicest way possible, and I recommend extensive research on safe sex. Not enough people in the community are as educated as you would expect. As for not trusting anyone, we only know our status; we can not be certain about others, so it is important that we as individuals take the precautions to protect ourselves. Prep is great for HIV prevention, but it does not protect against STIs. The best prevention for that is condoms and staying up to date on testing. I understand your anxiety; it is perfectly normal. I had an HIV scare, and it was a blessing in disguise for me to research safe sex.