I couldn't fuck her anymore

I have been a white boii for years but suddenly from last few monthes it had gone to other level. I started to dress CD while watching porn and i goon daily to bbc porn and now when we did recently i couldn't stay hard for fully. It is limping i have to think about bbc porn while fucking her thinking her of with bbc. My gf started to tease me of being a cuck and cuck within 30 seconds after that. I have gone to irreversible stage for now Don't know where it will end for me