It sounds like you're experiencing a lot of different emotions, and you're not sure what they are trying to tell you about yourself. In other words, it sounds like you're not really sure who you are and what you want. You just "happen" to trip over your current partner 5 years ago and said to yourself:
"Hey, being with him works good enough".
My suggestion is to take some time and really explore yourself internally. Theoretically forget about your partner and everyone else in your life you are romantic and sexual with. Forget about poly too - just for a moment or two of contemplative time.
While you're doing this, ask yourself who you are and what you want from life. It sounds to me like you haven't found the answers to those questions yet. Its hard to ask a lover to give you something when you don't know what that something is. Its hard for anyone to give you something when you don't know what to ask them for.