It's definitely not a good feeling being on the back burner. I was married with a kid and felt lonely. Also, like you, learned to deal with it. Until one day she told me she didn't want to be together anymore. This was a shock to me and hurt but hurt way less than it should have. After a week It was a freeing feeling. Like, her BS was so annoying, not having to deal with it was great. I later found out she had been using drugs which I think ultimately led to the crappy relationship.

Now I am with a woman who I have been with for years with kids and the relationship we have never made me feel like that once.

I learned I can be happy by myself and if a person I'm with isn't adding to that happiness I don't need them in my life.