Gf tested positive for a a sexually transmitted disease 34m 36f

So my girlfriend of 2 years tested positive for an A SEXUALLY TRANSMITTED DISEASE and she blames me. She said that I gave it to her but I haven’t been with anyone since me and her started hooking up and shortly after started dating over 2 years ago.

I went plus got tested after the girl results came back as an std. my tests came back damaging.

She tried blaming it on one of her sex toys she recently bought and then said she might’ve gotten it from a bathroom seat.??? Then her disagreement switched to it was me who gave it with her after I refused to believe that she didn’t cheat. What makes it worse is she got the std in the girl fucking mouth which is why the lady had to go to the doctor in the first place. Every time we talk about this she just blames me personally and throws a match. She basically keeps up until 3 am every evening until I can’t combat anymore and go to sleep.

She is currently out of city for work and I’m almost 100% she is performing her own thing. She known as 1 time in 2 days and is barely texting me saying she is sleeping.

I have no one to talk about this particular and I’m considering vengeance while Im home alone for the next few days whilst she is out of town. Need some help on what I should do.