Karen I am sorry you are going through such a funk. Being in a SSM stinks so much. I can remember after my son was born you would think the guys are climbing the walls waiting for the 6 weeks to come. My husband never said a word. But then again I had been taking care of him during those 2 weeks.
But to go for a year and not say anything to you. Not try anything. I think it could be a possibility that the gay thing could be a factor. I have been one that is familiar with your situation by reading here for awhile. OR as much as you may hate to think it there could possibly be someone on the side or an addiction to porn. Karen if I were you I would start to do some heavy snooping. I know you said it is hard as it is his work computer at home. But there has to be a way. I think you need to snoop for your own piece of mind.
Have you tried talking to him at all? I think that has been one of your biggest mistakes is not taking this on a very serious tone with him. He may not honestly know how much this hurts you.