Shamrockmommy, I am sorry you are having a tough time! I can relate to the new town/no friends/cabin fever time! I have gone through this myself more than once!! And I have 4 homeschooled kids (which I bfed longterm and had 4 c-sections, so I know how hard that can be too!) and I know how cabin fever with small kids is REALLY tough..
I am needing to lose about 65 lbs myself, and I am only 5'1" (BMI is almost 40%

). I find my hips ache sometimes too, badly, and I know it's from all this excess weight! I too have a treadmill but find it boring-plus I can't use it when my youngest (3yrs old) is up because I don't want her to try to join me, LOL!
I get discouraged frequently too... maybe we could help encourage each other to get on the treadmill daily and keep up with this NOS plan (which I really love, and though I haven't managed 21 days of successes yet I know I am changing my habits for the better one day at a time.
Do NOT beat yourself up about your slip-ups-we ALL have them!!! I have consciously started to MAKE myself not do that, because I find when I am beating myself up I will inevitably make it worse by eating even more or giving up entirely, and start the whole vicious cycle again. If I, on the other hand, say to myself-"it's only one cookie (or whatever), I can stop now and it's not going to ruin me if I just jump right back on the wagon right now it'll be fine", then I feel good about all the successes that I HAVE had...well then I am (first and foremost) feeling better (instead of worse) about myself because I generally have more success than failure. And really, it does no good AT ALL to tear yourself up for your mistakes..it doesn't get you back on track, it just makes you feel like ka-ka and want to stuff yourself all the more. At least it does me! And this will get you nowhere fast!
Make time to have fun with your little ones..I know it's hard, but maybe set up some things for the older baby to do -like blocks or cars or set them in their high chair with a toy or something while you work out, or wait til nap time to get in a few minutes. I feel funny posting this because I too have a terrible time making myself stick with exercise-but really it WILL be worth it!!
I am trying to encourage myself too with this post
Anyway, I sure hope you feel better...it does get easier, with the kids and the new lonely place..get yourselves on a regular schedule if you are not already and maybe that will help a bit with the lonelies..can you get to a play group in your area? I'm sure it would help you not feel so isolated anyway!