I have a gf but I went to madrid with my bros without her

We were basically only partying every single day for a week, i banged a spanish girl from club which is obvisouly not right for my gf, even tho she will never know.

But the worst part :

the last day, we went to club again, met a "girl" who looked very good. I was so drunk and took "her" at my place near that club, "she" gaves me a blowjob and i took her instagram as she told me she would like to meet again

Now being completely sober i checked her Instagram and ... i found out she is a trans, so basically she is born as a male but look like a girl

I feel like complete shit and im disgusted about me, the feelings i have are terrible.

Cheated on my gf 2 times, have done a "gay" thing i guess and also very scared and anxious to catch hiv from that blowjob as i wasnt wearing condom

Need some advice on how to calm down cause i just feel like shit