I'm not a teacher myself but understand it's an extremely stressful job.
Don't waste your time feeling mortified or guilty.
It would be useful to give more information, tbh, but in the meantime, try not to panic (although I realise that's easier said than done.)
I hope the following might help..I'm no expert, and these are just ideas off the top of my head.
Try to do some research to help you come up with techniques and tools to help you deal with the stress when you go back, so that you go back better able to deal with the stressful situations you will undoubtedly face again.
Try to keep to a routine, e.g. get up at a decent time (no choice if you've got DCs,) got for a walk everyday, eat well and also set time aside to relax.
It's very tough going back to work even after a small period of being off sick, so use these two weeks to build up your sense of well being.
Do you have colleagues who are your friends out of work? If so, try and make contact with them during the two weeks - maybe phone them this evening, this will make it seem less daunting when you go back, I think.
Good luck.
There'll be countless of teachers on here who have been through this and who will understand how you are feeling.
Take care of yourself and be kind to yourself.