For stopping by and getting drinks alone instead of going home to my 7 month pregnant wife and 2 year old daughter

I just feel I need time alone. Before my girlfriend and I dated she knew I was a bad introvert. I work with the mentally handicapped and I want to unwind when I get home. When I get home i usually help with dinner and taking care of our daughter. I love both of them and I feel guilty doing it but at the same time I just feel I need this. At work they started giving me shifts were I can get out later, and I’ve been feeling I should just tell my girlfriend that I’ll be taking that shift but maybe once every two weeks just go out and have a drink or some food alone. My girlfriend won’t be alone since we live with her parents. And she always gets the help that she needs.