@SophiaLauren
I have wondered if he's depressed. I've asked him. I wonder if he's gay... but I just keep getting this gut feel that he's never really been in love with me. He was about to be left on the shelf then I came along and was his last chance of family life.
Do you think the same is true for you though?
In your first post you say he's never been attentive or affectionate, even at the start. And you weren't happy with it. But you stayed with him and had three children? Is it because you wanted family life so much you thought you had to put up with a relationship that didn't come close to satisfying you?
So there are a few deep roots to your problem. There's the societal one. We see this problem come up all the time here - two people who weren't compatible, didn't really love each other, sometimes weren't even attracted to each other, who somehow got all the way to married-with-kids because society keeps hammering it home that no other lifestyle is valid.
Then there's your mother, who has ground down your self-worth so much over the years that you don't think you deserve and can have a relationship with someone you like, and who likes you back.
When some marriages run into difficulties, couples counselling or working on it is good advice - but that's only the case if there was a strong foundation. Couples can lose their way but if there was love there to start with, there's hope they can get back to that.
I'm afraid that there's nothing here for you or your husband to find your way back to.
You would be much happier calling it quits, as hard as that may seem now.
You also need to go no contact or at least low contact with your mother as a matter of urgency, and absolutely stop confiding in her with any of your problems.