Loves Limit

I have been with this one perticular female, on and off, for about 2 1/2 yrs. She has a son, who I love so much. I do "care" for her but the love that should be there is not, and I've been with her since I was 18. I'm wondering if I should try to work it out because of the amount of time put into the relationship, her son, and my comment that I made ( not marraige, just a promise). I am just now come face to face with reality. I am a grown man making my own money, and trying to start my life. Does any one have any input on this situation