Marriage has a deadline

I am sad to say that I am approaching 50 and have spent most of my life with people who dissappointment me. My parents, my husband. I do not have that high of standards that they are impossible to meet but I seem to be a magnet for people with ADD, why is that I can't figure out. being the daughter of an ADD person you would have thought I would not have married a man with it also, Ahh but it was hidden so well...and oh the romance was intoxicating.   I read Melissa's book maybe 2/3 years ago, H read maybe a few chapters just the amount he could in one night and never picked it up again...said yep thats us. end of story, I need to read it again as I need help.  I am so miserable, hate the person I have become,  I have decided I am going to give it one last effort on my part, as I know some of our issues are my fault, and if within a year (if we last that long) I am still just as unhappy I am moving on.. instead of a Birthday cake I'll have a Freedom cake. After spending my 30's and 40's in this crazy relationship I refuse to spend my 50's doing the same old song and dance.  I am not afraid of being alone, I am only afraid of what would this do to my children, i know they do not want us to split, but living with parents that can barely stand each other isn't good either.  I moved out of my parents house at 18 as I could not take it anymore, I lived independantly until 30 never needing a dime or help from them, and somehow went from the object of a mans affection to an indentured servant.   I do have to say though, growing up with an ADDer who couldn't handle much of anything it did teach me to be strong and I learned early how to take care of myself.

I have work to do on my part, when he does little things for me I don't appreciate them, it is hard to appreciate a little thing when there are so many big things wrong.  When the boys do something that irritates him and I think he overreacts i sometimes say things that don't back him up...I know that is a big issue, but I hate to see him treat the kids the way he does and I have a hard time not saying something.  He does so many thing that drive me insane, but I cannot make him change...I know I can only change how I behave and react to them.   Whats that old saying ' give me strength to change the things I can....and accept the things I can't, or something like that....I don't know if I can accept the things I can't change, but I certainly do need the strength to change the things I can...and maybe there will be a trickle down effect.  I need help..I can't live like this anymore. Any suggestions on self improvement.  

(Not ADHD suggestions, he was diagnosed many years ago, we have been to several different counselors, he has meds but takes them erratically....he needs to want to change, I can't do that for him.)