Wow....so many things run through my mind in reading your request. Obviously you are very unhappy in the way you currently live your life.
20 years is a long time to walk away from. Have these problems always existed or did you only begin to notice them after you retired?? Or, did the problems begin recently? If you are sick of it now, it must have been ongoing for months at least.
I guess, though...my first question is do you still love your husband? The reason I ask this is because while you listed your complaints and want suggestions on how to resolve it, you never once mention how much you love your husband.
As for your happiness and the things you want to do so your life isn't dull any longer. Go do them. Your husband is not responsible for your happiness, you are. You may wish to enjoy some of these things with your husband...but have you talked to him to decide if they are things he has ever wanted to do? If not find a friend with similar intrests and enjoy them with the friend.
Regarding his not helping around the house and "wanting to sleep half his life away", Haveyou always done everything and maybe now he's retired too and can help out. Have you discussed changing household duties so you can both have part of the day either to yourselves or to do something you both enjoy together? If he is still working are his hours such or the work a type of physical labor that leads him to want to rest when he is home??? Then maybe some chores that will balance out odd hours or physical labor (maybe he can keep help the kids with their homework and you clean the house...stuff liek that...
The sleeping thing (that he wants to sleep all the time) could be that he is not resting enough because of the snoring or it could be a sign of depression. Only a sleep study will give you more information on that...IF he still has his tonsils and adnoids you might consider having them removed...enlarged adnoids can block the are passage causing sleep apnea and temporary loss of air into the lungs. Which makes the snoring worse. Deviated septums do the same but in a different area. Both of these can be fixed with surgery.
I do, however suggest you two seek couples therapy. If he refuses to do that, you might want to see someone on your own, so you have a safe place to vent your frustrations which will allow you to better focus on what you want, what you are willing to live with and what you won't.
I hope this did not come across to harsh...but there is so much not said in your request...I hope you are able to work things out in the best interest of both you and your husband and I hope you find the happiness you seem to be searching for!!! ;-)