Hi L.,
I can see how resentment would build quickly, and isolation. Are you and your husband able to find time to talk to each other about important issues like this? (Difficult enough when you are both in the same location.) Does he know how you've been feeling since you moved? Do you have other local support (church or something/someone) with whom you can talk?
Is your 5 yr old in Kindergarten now? Depending on the school, you might be able to bring your little boy along with you to her school, where you could get involved and meet new people. If the school has a website or newsletter, you could insert a comment like you did here about being new in town and wanting to make connections - I'm sure you're not the only person new to town.
Years ago when I lived in Guilford Co, I was active in La Leche League. I know you're probably not breastfeeding, but they are still a great resource for where to find other mothers - even mothers of older children. You might want to look up a local group and see if someone has some ideas for you.
But I guess you're looking more for empathy and suggestions as to how to deal with the seemingly endless lonely times. I've not been in the situation, but I bet so many wives of active duty military spouses, wives of long distance truckers, spouses who travel extensively, etc could help you out with good advice. Maybe if you posted a note (here, and on any number of internet groups) with something to that effect in the subject line, it would draw attention from those in similar situations? Just a thought.
I wish I could help more....I just wanted to reach out to you and wish you luck with your situation.