I need a bit of help
Hello Mememo, and a warm welcome where I have seen you reply to many other comments.
I am definitely sorry about being physically assaulted and hope you are not suffering from any injuries, this and your boyfriend having an affair, as you say, it's time to let him go for your own health.
I am not sure 'revenge sex' can happen, because it's a physical connection between two people, but you need to say good-bye as he is only using you and your house for his advantage.
This may help you connect back with your flat-mates.
It's great you are doing yoga as well as art, a terrific combination.