Hi and welcome to our little family. I will say, right off the bat, that I have no experience with the problem you are sharing with us. How's THAT for some great advice? You say your b/f is afraid he will have an anxiety attack if you try making love. Really personal questions here.........how close have you two actually come to having sex? Does he get to a point that he has to stop for fear of having an attack, or does he not even engage in any sort of sexual play? Is he open with you about his past? Has this happened to him before?
Someone with much more knowledge than me needs to be offering you advice. How can you help him? Seems like you are already doing that by not bailing on the relationship or making him feel guilty. He must be worth the wait. Most women would have ditched him by now. This says much about you and your compassion. Is he on meds for his anxiety? Some meds will interfer with sexual arousal. I'm certainly NOT calling him a liar, but perhaps his problem is an inability to sustain an erection which causes him embarrassment? Is your relationship such that you can discuss this possibility with him? Is he in therapy? If so, could you suggest he discuss this with his therapist? If he is in therapy and sees a woman, he may be too embarrassed to tell even her. I might suggest he see a urologist (male!) to rule out any problems in that area. Sounds like you care a great deal about this man, want to take your relationship to the next level, are willing to be patient and non-demanding (I hope) and what you can do to help at this point, in my humble, uneducated opinion, is to stand by him while he is working this out. The relationship could only be stronger for your support. I admire you. He is a lucky man. Keep us posted.