Hello 2girls3boys, and a warm welcome to the site.
We aren't doctors to be able to give you a diagnosis but can suggest, but firstly, your day must be so complex looking after 5 children and whether or not you do have PND is for your doctor to determine, although it may be highly likely from what you've told us.
You can't be intimate if you have no desire, and your husband needs to appreciate this because each day means you are occupied 24/7 with the demands of not only your children but also your husband and what else needs a decision on, so your day is full, so please don't feel guilty at all.
I've suffered from PND myself and know how intense this makes you feel and suggest that you try and find time to contact your doctor, this is very important, cause you can't handle this alone and even talking with your husband is not the same as with your doctor.
Sometimes in life, we need to put ourselves and it's at this point to ring and make an appointment, then plans for that day can be organised.
All the best.