Your last sentence is very powerful - and often many of us are more committed than you are when we realize this - and we go through a period of trying to decide WHAT'S IN THIS FOR ME? And of course that is much more complicated when there are children, mortgages, etc.
You sound like you are doing the right thing. Standing on the precipice of a committment and realizing that this relationship will not, for at least the short term, be 100% fulfilling. That isn't to say it couldn't be someday, but that's the gamble. And that's your decision.
I love my husband and I love the things our relationship has given me - children primarily and some really fun happy years. But I know I have given up many of my needs so I look at you with some envy