Kelly
the young men in your age group typically do not respond well to single mothers.
You have several options.
1. Dating slightly outside of your age group,
2. Contacting your local parents without partners group
3. Involving yourself in local mised social groups
4. Involving yourself in local church groups.
If you would prefer to stay in the 18-21 yo age group, then it becomes a numbers game. By that I mean socialising as widely as possible (with friendship in mind as a starting point) will give you the best chance of meeting a young man mature enough to appreciate your responsibilities.
Mike