I have been in a desperatlety uhappy marriage for years?

Tell your husband what you just said here!!!!! Maybe he doesn't even know how unhappy you are? Maybe he is unhappy too, why does he go to the pub all day? Ask him to try to work on the things here you have said upset you. If he doesn't care to change or won't then at least you've tried. Now is the time to enjoy your husband, as your Companion, the children are grown and gone. There are a lot of lonely people out there that just don't communicate.