I think wanting a partner is natural, how we're made. We aren't build to do it all ourselves, we're social animals. We can "survive" by ourselves but it's not our natural state.

I'm not going to suggest match.com :-) but I think you do need to go out and meet other people, make some friends if you don't have them, go out with them more often if you do. You have to live your own life, your children have to live theirs and work is not supposed to be one's whole life either. If you don't already journal, I would start, see where your hopes and dreams have gotten to and start moving in their direction?