confused

I don't know what to do my husband never wants to be intimate with me anymore he says he is impotent I feel he just isn't attracted to me anymore it has been about a month since we have actually been pleased sexually although the other night I caught him looking at porno on the internet that really made my selfasteem hit bottom at first he denied it then he admitted to it and said he didn't know why he was doing it then he changed his story last night after I asked him why he never wants to be intimate with me anymore then he said that he was looking at porn to see if he could get an erection I don't know what to believe anymore and I am so hurt and frustrated I just need someone to talk to