I'm not sure where to start, I'm stressed out as fuck right now, I'm sorry. I just need your advice and support.
So I'm 22 years old white male, living in Germany with my mother (father passed away 4 years ago) and my 17 y.o sister.
Since like middle school I had a frend named Bernd and we used to be like soulmates. I'm a bit autistic, so it was always had for me to maintain social contacts, so Bernd was the only person I've used to be friends with.
As we grew a bit older (18-20) years old we realised that we are an absolute example of a typical incel and this idea was one of the most important until now. Foids ingnored and rejected us all the time, so we gave each other support and understanding just like real friends do.
So a bit later me and my bitchy foid sister fought over some useless meaningless shit and as a revenge she fucked my best friend and texted me about it. I didn't believe her and called Bernd and he confirmed it. He apologised, but I'm feeling so betrayed and disgusted right now. I've really never liked my sister. I want to strangle her to death for taking the only person I could be genuine with.
I have no idea what can I do about it.