In my opinion of you are bi- you are still gay but that is just my personal opinion. I am sorry you are going through this. You say this is an arranged marriage, is there any way you can get out of it. I do not know where you are from and if you can divorce or not. I am not one for people just calling it quits but in this situation I would.
Ok, first. He is bi. Second. He is having sex with these guys. You need to stop having unprotected sex with your husband and go get tested for HIV. For a conclusive test, it has to be done 3 months after your last unprotected encounter with your husband. Your husband may be having unprotected sex with these men and could easily catch HIV. This is a very dangerous situation. I would leave the marriage for your safety and peace of mind. Good luck.
Can you leave? What is the cultural basis of the arranged marriage? If a man is cheating, his wife has every reason to leave, even if he were just cheating with a woman and none of this bi or gay stuff involved. Given that it was an arranged marriage, I assume it is a very traditional culture? If so, he should let you have a divorce because he would not want the fact or issue of his being gay (or bi) out there.