New here and could use some help....

I've been married to my husband for almost 12 years. He is a wonderful man, everyone's best friend, would give a stranger the clothes off his back, outside of the home. On the inside, I've felt like I have been going crazy for the past 12 years. I feel as though I am in constant fight or flight mode. I guess I don't understand. I've suspected for quite some time that he has ADD/ADHD but he will not get tested. We went to counseling once where he admits to having it but states he does not want to take medication and feels he can manage it. We quit going because he told me he felt as thought I made him look like a constant "dick" in our sessions. So, I once again just gave up. Some of the things that he tends to do are:waiting to the last minute to get ready if we are going somewhere, underestimating the amount of time it will take to complete a project then getting pissed at himself when things don't work out the way he thinks they should, zoning out on the computer, he is constantly on his cell phone....talking to people or texting people, I seem to get blamed for 99% of the things that go wrong...somehow everything is my fault, he is obsessive about how clean the kitchen is but doesn't care about the rest of the house, he tells me how unorganized I am, he expects perfection from our children (we have 3 boys and I have a daughter from a previous relationship who does not live with us....her and my husband do not get along...) he expects them to sit still, be quiet, etc....my husband expects me to be at his every beck and call and to "help" him constantly which usually results in him getting mad at me for not helping correctly, If I am talking about something at work he constantly interrupts me to tell me something about his work making me feel as though my information is not important enough, my husband is always right...even when he is wrong he is right, he makes a commitment to do something then decides at the last minute he doesn't want to do it because it is too hard or too much work, we make plans to do things then at the last minute he finds a way to get out of them, I feel as though he is constantly sabotaging me...my friendships, my weight loss, etc, he says he will support me but then never seems to follow through with it or he will find a way to berate me or accuse me of something, everything seems to have to be on his terms and done his way, he tells me that I never listen to him and I don't support him, really the list could go on but I will stop there.

So, all in all I feel like I am going absolutely insane. I've gained 40lbs (which I am trying to lose), I cry alot, I try not to engage him in arguments which just seems to infuriate him more, I tackle all the household chores because he is always "too busy" to do anything. I deal with our children the majority of the time because he doesn't have the patience or he is "too busy". But yet when asked he will tell you how much he does around the house and he doesn't understand why I complain so much. I worked full time also and I work 3rd shift so I just feel constantly run down. My husband has kept a steady job and he is really good at what he does. He is very focused at work, organized, able to handle things but when he comes home it all seems to fall apart. I try and tell him how I feel but that just ends up in an argument because he feels as though I am attacking him. He isn't very "loving"....his idea of showing affection is grabbing my breast or slapping me on the butt....he can just act very immature for his age. It is almost like he feels that everything and everyone should revolve around him and his thoughts and his ways. All in all, I am sick of crying, I am sick of fighting, I am sick of feeling broken. I left him once for about 6 weeks and he really did make some improvements and now it feels like we have done a 360. I'm lost. I don't know where else to turn or what else to do. I don't want our marriage to fail but yet I don't know how I am going to survive like this for the next 50+ years.....I can't go back to counseling or he will accuse me of wanting to leave again....I have no one to talk to....my family can't stand my husband and this has created a huge divide between us....I'm just lost....so any help or information, anything, would be deeply appreciated. Thank you in advance!