For example I often have the thought, "who does she think she is ignoring me and treating me like dirt, avoiding affection and even listening to what I have to say about even mundane topics? why should I even try to be nice to her when she is being so dismissive of me?"
Not saying that position is defensible or logical, but that is the sort of thing that has kept me withdrawn for a while now.
Hmmm. My only suggestion would be that rather than JUDGING those feelings immediately, you might try looking into them even more. Judging your thoughts/feelings without understanding why you feel that way or where those thoughts are coming from short circuits your ability to get to the root problem.
How would your wife respond if you did say to her "I feel like you ignore me and treat me like dirt?"
I'm not saying you HAVE to ask her but asking what you think her response would be. Have you ever told her something directly? I think I remember you using phrases like "How do you think I feel when you a,b, or c.?" but that is a passive way of talking with her. Just asking and brainstorming!!
But what is happiness except the simple harmony between a man and the life he leads? ~Albert Camus
