My situation is very similar to yours. I have 3 teenage daughters who now live with me most of the week. My wife is so bad a doing things with them that I have had to come up with ideas for the girls to do with their mother. I have stopped doing it because it starts to feel like cake eating. I feel bad, but it is up to my wife to do this on her own. She is the one who started down this path.
I feel bad for the girls more than for their mother at this point. I do try to do a lot for my girls. I have also found it difficult to do things for my self. I find it difficult getting going sometimes and get down a bit. I think this is normal as long as I don't get stuck.
I have decided that if I can't get away from home, then I need to get back to some of my own projects that were just for me. I have a mahogany speed boat that I started before I got married. I am going to move it into her old spot in the garage and get onto it. I can be home, but escape for a little while into the garage and do my things. I will be doing something for myself and not vegging in front of TV lost in my own thoughts and getting down.
I would suggest you try and find a project or hobby for yourself to escape into for even a hour at home. It will be something for you to escape to when you find yourself getting down.
Twisting on Life's Rope Me53 W53 M20 D21 D19 D16 BD 2-2013 D final 1-2015 _________________________ "Dream about tomorrow, Live for today, Learn from yesterday"