I'm a bipolar mom and found that the medicines dulled my reactions to everything including driving. Seeing that you are the only parent right now having a dulled sense of responsibility isn't really a good thing. However being on you own and probably anxiety filled about potential dangers of you husband's absence or delay in his return home can also be triggering episodes.
There are several factors in Bipolar that you must consider and if you haven't addressed them then the medication or going with out medication will not give you the effects you deserve. The first is other hormones. That's right, a shift every month can make things worse on either pole of behavior. But every day hormones like low thyroid, high blood sugar can keep the medication from being as effective and make the side effects worse.
I've found that a strict routine, plenty of exercise and lots of rest are the best thing to keep me going now that I don't have medications for my conditions. I use FlyLady.net to manage my house. I use The 4 Agreements by Don Miguel Ruiz to manage my out of control thoughts. Check into the local library and see if they have a copy, if not see if they will borrow a copy from the Tulsa library system.
Believe me, I know how hard it is to do this alone with kids. The most important thing you can do right now is give yourself time away from the kids and the pressure. Find a friend or family member that can take the kids for the evening and go see that movie come home and shower, shave, moisturize, meditate, take a power nap anything for you that you don't normally do then go get the girls and get them off to bed.
Nothing will boost your seratonin (good brain chemicals) better than exercise. I just bought a bean but I had been doing pilates as well. I'd say that you are doing pretty well to have reached out. That's a good sign. Keep up the extra effort and when your hubby comes home work hard to reintergrate him into the life you have not the other way around.