“When I think about committing to her, I tend to focus more on our differences; what i’m giving up vs. what i’m gaining. People have said to me the grass is always greener on the otherside, and I understand that yet it still doesn’t help me understand my feelings.”

The grass is greener where it’s watered and given care. Given care to. You do give up some of yourself as being a priority when you commit to someone and you gain things you can’t give to yourself. But if you aren’t ready to give care to another you aren’t ready to get married. It won’t be perfect at first, but you at least have to want to try and do and to keep trying and doing. Think about it and at the same time do as the other responders have said and talk to her.