On the brink of giving up

Hi all I am new here so please bare with me, I have been with my husband scince we were 13 and we had our first child at 14, we now have two children age 14 and 7, our 7 year old is deaf and disabled so as you can imagine life has not been easy for either of us. My husband was diagnosed with adult add after his mother recommended he saw the same doctor who diagnoised her, When he was diagnosed about 3 years ago it was, at first a relief to him and me and the medication seemed to help.. We went through some problems and saw a marriage counsellor and did split up for a while but seemed to have sorted things out, whilst we were seperated my husband stopped taking the medication saying that he felt better off it and has just recently  begun taking it again. The problems I am having at the moment have been going on forever but i think Im just getting fed up of dealing with every thing alone I understand his add hinders him slightly but how do i know what is add and what is just him? I think he has become so used to the way he is I dont think he sees a way of changing I dont want to sound like im putting him down because I love him very much but just some friendly advice on what i could do would be of great help.

I suppose the biggest problem  i have at the moment is his complete and total self obsession he thinks only of what he needs or he wants I have to constently remind him to try to think of others, he has just started taking the ritalin again (about 3 weeks ago) and he is on antidepressents, the ritalin does seem to help him focus but again on himself he can spend hours and hours on the internet and as soon as i ask him to do anything becomes very grumpy He is very withdrawn all of the time and seems to have something new wrong with him daily, he is constantly shouting at the kids and his relationship with our eldest is at rock bottom as he feels the need to make comments on everything from the way he eats to the way he dresses he also does this with me he always notices something wrong and is constanly complaing this needs doing or we need to do that, he also seems to have an obsession with smells everything smells so much so that even after i have wahsed and cleaned my teeth i lay uncomfortable in our bed as i know he will mention it this has even led me to sleep on the sofa. We have talked this through a million times with always the same response sorry I know what Im like but the thing is I dont want him to be sorry I just want him to be happy and hes not ever. When he is in the house its like a tension in the atmosphere and the worst thing is he just seems so unhappy and angry all the time I have felt guilty in the past but I know now that its not me I want to help but I dont know how. This has been going on for years but has got worse because i am now working full time and he is not I try to be supportive but its draining to always be the supporter we never laugh and talk and sex is also a no no. we have been or sorry I have been working on this for years and nothing ever seems tyo change is there something i can do or are we just doomed ? thankyou for taking the time to read this I know I have harped on but its just a relief to have someone or sompe people to talk to that may understand thankyou again x Ps he also talks to his mother at least 5 times a day sometimes more