I come this board
I would not jump to any conclusions. Maybe it is something very personal that he is not comfortable sharing. I would speak to him and just say that you are worried and would like to know if something more serious is wrong. When I read your post, first thing that came to my mind is that maybe he cannot get aroused anymore so he went to see the doctor for that. I could be totally off but still I would not jump to any conclusions and take it personally until you know for sure what is going on.
Welcome back Ami_99, it's been a long time since you posted here.
It sounds like he doesn't want to share this with you right now.
Call his doctor and ask what is going on with your husband. If hubby doesn't tell you straight, you need to find out for yourself. Perhaps your husband is having some kind of pd (penile dysfunction) and is embarassed to tell you. He could have a problem with his testosterone levels, which could be the reason for his detatchedness. You can then tell him the dr. phoned and that you know about it and that he shouldn't feel embarassed.
Doctor-patient confidentiality and HIPPA won't allow his doctor to talk to her about any problem or condition her husband.might have.