Okay.. so she thought she caught something from you, which means she assumed you had it and gave it to her, and she was okay with that. So either you don't believe you're her only partner, or you feel like her having something, even if you gave it to her, somehow makes her tainted and unsafe? Maybe this is a bad analogy but it really reminds me of guys shutting down when they find out their girlfriend is pregnant as if they had nothing to do with it and it's all the girlfriends fault. This was an "us/we" problem and you went "every man for themselves on it" lol I'm not sure if this is fixable and if it were I'm not sure you're emotionally mature enough to be capable of fixing it. You got some self searching to do on how you handle things as a team in a relationship. What is one of these tests came back positive for one of you two? You'd just end the relationship. And in that regard, you showed her your hand. Maybe I'm missing some nuance but this sounds very self indulgent on your part

YTA