How can I stop myself frombeing so scared of AIDS? in order to help my boyfriend as his brother has it?

Hi, I have mntal illness and for a good few years suffered acute OCD where germs were my main phobia. I have recovered from that now but still have to be very careful I don't slip back into it as it almost killed me. My boyfriend and I have had a rough time and were just starting to get on our feet, he has had many recent deaths in his immediate family and has been strong but I can see he is at breaking point. His brother recently was rushd to hospital and they discovered he had cryptococcal meningitis the type ociatd with AIDS. My boyfriend aftr all he has just been through now had to face the fact that his brothr has AIDS and may die from this AIDS related illness. He is so hurt and I am finding that I am unable to be ther for him. I know he does not have aids and he needs me so bad but I have found that my mind will not physically let me touch my boyfriend because his brother has AIDS. I try to comfort him but can smell illness on him, he looks sick (he is just stressed but looks ill to me) and each time I see him now I feel nausiated and disgusted even though it is not him that has AIDS and evn though I know it is wrong to fl that way and be prejudice about anyone with AIDS. I can't help feeling this way and I have broken my boyfriends heart by not even being able to give him a hug to comfort him through his rough time, I am trying but cant shake it no matter what. It kills me that I am being this way and hurting the man who has ben there for me through everything and if the roles were reversed I know he would have no hesitation to be here for me. I don't want to do this to him but I can't stop the way I fel, I dont know how. I remember when I had really bad ocd I have a small companion dog whom I love mor than life itself- when I had my acute ocd I wanted nothing more than to cuddle her, but each time I tried I could not bring myself to do it, I becam physically ill and found myself feeling disgustd by her, I couldnt touch her for 2 years unless I was pumped with 7 valium, I am over my ocd now but I am finding that in this cirstance with my boyfriend I am feeling the exact way I used to fel with my companion dog when I had ocd. I want to stop being lik this so I can help and support my boyfriend and not lose him over this but I physically cant and dont know how to change this? Please help what can I do? My boyfriend doesnt understand why I am like this I told him I think its my ocd but he does not understand he thinks I dont love him and I do more than anything I just cant do it I really need help it is killing me that I am hurting him so bad