Good luck, muffin, I can completely see why would one feel overwhelmed. I also think it has nothing to do with the actual logistics, etc..It is so nice to be able to raise your children in a complete family and comfortably be used to cooperating involved husband sharing responsibilities. So, it might feel overwhelming, at first, especially if you are by nature a worrywart like some of us. You can do it! You might actually really enjoy it, haha...Men complicate things at times.
I can easily pull off mothering without a car, too, so I am also relearning to drive again, at my pace. Besides, who has the cash for gas these days? Another thing is, people tend to forget we are in a foreign country (3 years stuck with kids does not allow one to actually get much independence, especially if money is short) where things don't have to work smoothly in emergency situations, I have been there, what does one do if you do not speak the lingo,etc..But don't stress yourself with scenarios. Moms are high on stress hormons as it is, even a year after delivery, perfectionists by nature fretting over everything, etc.
I can only suggest to visualize the positives - sometimes hubby gone means less work, forget schedules and school times, have a blast feeling you can do whatever you and your kids feel like. If you need moral support, let me know. Stock up on dvds, kid foods and snacks, have a pizza or whatever delivered, stock your freezer before your hubby leaves, lower your standarts, don't bathe your children every day, change clothes only if dirty, housework can wait, have a back up plan for real emergencies (hospital, injury, etc), have your hubby, family or friends check on you, we can check on you too, if you need to. I agree - forget the school, have friends come to you for playdaytes! I forgot where you live, pm me if you need anything, really, even if you want to vent. There are few more moms living nearby.
Your little one will be selfcontained, here are some sites for
indoor fun with tots ,
some more , etc...
Reduce your activity mode to walk around a bit with kids, look at things together, blow bubbles, walk to the nearest store (carrying your little one, wearing him, will leave your hands free to chase after your tot), have a backpack, leave the stroller at home. You can buy a carrier cheaply at a thrift store, before your hubby goes.
If you can, try to calm down so your babes don't pick on you being nervous. Your hubby will have a blast, now I seriously think you and your kids deserve the same.