Oh I'm so sorry things are tough atm. 4mo is such a tricky time, one of the worst for us as I seem to remember DD went on nap strike completely. I too went out of my mind.
There's a huge GS that happens around now too, are you feeding at any of the NW's? It must be terrible with the early teething as well. You have my utmost sympathy. Ibuprofen is best for teething so you could try medicating before BT and see if that gets you a good stretch in?
If you've reduced the A time, I would actually try going back to closer to the original A time for that first A and see if that makes a difference to the first nap? If that is short, I would only reduce the next A by 15mins or so rather than 30. I wonder if you've gotten into a bit of an UT/OT loop there too?
If you could post yesterday's easy in real time for me, we'll take it from there ok? Hugs in the meantime xx