You are off to a great start just by seeking support online. I also agree with the others- playgroups, story time at the library, etc were my saving grace when my boys were younger. My husband joked that "stay at home mom" didn't describe me very well because the boys and I were always on the go.
If you belong to a local church or place of worship you may meet some moms there as well. I also met other moms at the pediatricians office, etc. Consider taking a class or joining a book club one evening a week and getting some adult interaction that way.
Take care of you- it makes for a better (and happier) mom