What kind of help are you looking for?
What is it about your current situation that is "not working" for you?
If you are looking for advice about your specific issues, you'll probably have to go into a bit more detail about your situation.
The textbook response to what you have written so far is this:
Adding more relationships is not something you do to "fix" your existing relationship. You need to have a solid, stable foundation with your current partner(s) in order to entertain the idea of pursuing additional relationships.
Judging from the fact that you found an existing thread to add to instead of starting a new thread, I would say that you have been doing your homework and reading/researching on this site and elsewhere, so you have probably read what I just said in some form already.