You are doing brilliantly.
I have been where you are, my DH works away and I had a new born and a 20 mo. I know the panic, the shouting and then the guilt.
I remember sitting all three of us crying.
It does get better, that I promise you.
But for now, you need some quick fix solutions. It can seem almost undo able to get coats on and get out. But out is so much better than in! Even the supermarket?
My NCT group were amazing, I was on my second baby they on their first but the support I got was immense and I only had to ask. I felt awful and embarrassed sometimes asking but on the other hand if they have their DH to help and you don't even if they have other children they could come round for a bit. Just text them, you never know.
I am a planner and planned something everyday. Usually the morning. But I know the fear, the panic and the utter helplessness you feel when you see a whole day ahead of you and you just don't the you'll cope.
I just wish I could help.