B.L.
I also suspect you might be suffering from some form of postpartum depression. It's a very common thing, particularly when a new mom feels somewhat isolated, like you describe. The times of greatest risk for PPD are times of significant hormonal change -- about 5 days after birth, when a woman stops nursing (particularly if it's not gradual), when your period starts again, etc., so be particularly gentle to yourself if you know any of these things are coming.
I do think you should try to see a doctor or a counselor, but if you can't, there are very likely to be some free or inexpensive new-mom support groups in your area that you can go to and find women in a similar situation. Are you nursing? You might be able to find support at a La Leche League chapter in your area. Birth and Postpartum doulas often have resources for new moms -- I'm almost certain that if you call a few in your area (and you can find them at the DONA website -- www.dona.org) they would be happy to help you connect with someone or a group or something.
Making new mommyfriends is a very good idea. It's always a little easier when you have someone who can commiserate with you. Playgroups are good places to meet other moms with children about the same age as yours. Does your town have a mother's club? They often put together playgroups. Your local library might have a storytime where you can connect with other moms. Another place you might be able to connect with moms is a church/synagogue/other congregation -- they tend to be very community based and often run things for moms and children. You might be able to find some inexpensive Mommy-and-me classes.
Good luck. Feel free to write to me personally if you want to talk.