You are unhappy - HE makes you unhappy, at the most basic level, this is a no brainer. What exactly is it that he thinks you are expecting that is aiming too high?
I suffer from deppression and i have to be honest, it does affect my DP. But he is supportive and understanding, now - it took us a while to work through it.
i think you should save this thread to remind yourself just how low HE made you feel, you couldn't even type properly :( HE makes you feel like this, HE makes you feel that your children don't love you - HIM!!
Do you absolutely have to go back today? Can your oldest access treatment from where you are? If you need anti-biotics or anything like that you can go to the local walk in centre - the one near me is excellent, hardly a wait, drs are also there so no problems with prescriptions and a pharmacy downstairs.
If you can stay, because he shoud be doing the running now - he is self employed isn't he? so if he really needed to he could get his arse down to you and sort things out, instead he is waiting for you to come home with your tail between your legs after what he will see as your little sulk - fuck that!
Stop trying to justify things - he needs to change but he doesn't think he does. There is probably work to be done on both sides, you are willing to work at this, he isn't, the problem is, you cannot make up for the deficit by working yourself to oblivion, there will always be a gap.
He isn't taking you seriously, he thinks you are thrwing your toys, you have gone down to the caravan for the week with the kids, you may well have done that anyway. Don't let him dismiss you like this - you are worth more than that, so much more.