L.M.
How long have you been together? It sounds like quite a long time. It seems like you have fallen into the "same old routine" both individually and as a couple.
I know how you feel about sometimes just not wanting him to be arround. I love my husband, I'm still in love with my husband, but truth be told, sometimes I just want time to myself or I find having him arround is annoying. I only feel this way occassionally and have never thought of having another relationship or leaving him.
You've stated you enjoy his company, you go out and have a great time. Then do these things. They make you happy. The problem seems to be when you spend long periods of time together, so make them shorter.
There's no reason why you can't and shouldn't be happy now. You just need to find what that is and I'm sure it includes your husband.