anal..

okay so i have no one I can talk to about this & this is my last resort ha. My bf wants do anal really bad & I am NOT comfortable with it at all not do I enjoy it. Yes I've tried it just to please him but the pain is horrible & in no way did it feel good to me. Lately he's been getting ANGRY when I don't want to "Keep trying" anal because I am not comfortable.. There's been many fights just about ANAL !! like really !? But if I can just get some advice on what to do about it ... Please & thanks !