I self-harmed and over ate to numb the pain. I can categorically tell you that neither are the solution. So don't do those things 😉
Sometimes listening to self-help audiobooks in headphones was great - just to hear a positive voice in my head.
Sometimes just putting my head down and pushing through the day.
Sometimes taking naps in the day - even putting phone timer on for 20 mins to make sure I fight sleep the whole afternoon.
What made a good difference was getting out of the house. But I can't begin to explain how hard that was. I've known people train for and participate in ultra marathons more easily. If it's really too hard then opening the windows to get fresh air running through was a bit helpful. Definitely didn't do any harm to breathe fresher air.
Also listening to upbeat music on headphones (so it's IN my head) could take the edge off for 10 minutes - which is 10 minutes better than none.
I'm so sorry you're in this position. What I did may be useless for you. But maybe they give you ideas? It's just sh*t though. Nothing is going to make it suddenly ok. That's not a signal to give up, more a sign that you may need to aim for little chunks of time rather than sweeping changes, or tit can lead to feeling like you're failing.
And you're very much not failing, my love, life is just crap right now. 
On another note, you said you're on a waiting list. Have you spoken to your midwife about all of this? Some areas have perinatal mental healthcare, so perhaps there's away to get some help that way.