I agree with ^^ these two.
You have felt like this before, and each time you feel like this, you manage to climb back up.
Well done speaking to your DH, even though he is in the same house, it doesn't mean he realises the with of of feelings on any day unless you talk to him. Now he knows, tell him what he can do to help, a hug, a rest, a sounding board, whatever it is. Talk to your doctor too, for some options and some encouragement.
You will feel better. Remember the tools you can use to help yourself cope on the tougher days - sleep, and yes, that does mean bed straight after the children, regular food, some time outside every day for a bit of exercise, or even the shred (still not tried it!). And, some company in the day from somewhere. pop to the neighbours, arrange a playdate.
The doctor can help what you need to do on top of that.
Don't worry about the girls, my mum had PND and anxiety for a long time. if you asked me for my pre 5 year old memories are, I'd say the walk home from playgroup (my neighbour and I would hide in the same place from our parents and delight in it) and getting my fisher price school. No memories of any of mums illness.
Now I'm going to plump up those pillows so you get a good night sleep and get you a cup of cocoa. You get your jammies on.