My puppy is four months also. Potty training is very tough on the nerves... but We knew this before we even got the pup!!!
I am a little concerned about your pup not eating after 5:00 at night. That is a very long time for your pup to go with out food. Sadie gets her last meal about 9:30. I get up at 6:00 and take her right out and then feed her. These babies are still little... they need to eat often.
As far as potty training goes. Find one place to make as a potty and stick to it. We have potty pads in the basement in a play pen. She knows this is potty and she goes when ever I put her in it. When she gets older and it gets warmer...she will go outside. I have a potty pad in her expen but she never uses it. It's there if she ever wants to but so far nothing!!!
She still will go on my floor while she is running around playing during the day. I think she just hasn't figured out that she is supposed to hold it until she gets to the potty. I take her every hour or more...
If the create isn't working out why not try an expen. At least you puppy won't be sitting in his own poo. Sadie just got an expen for when I have to go out during the day. She sleeps in a create just big enough for her to lay down and turn around in at night. Her create is on a table, facing me as I sleep. I can reach over and get her out of the cage if I needed to. She likes to see me and be close. She never once has gone in her create. She has a water bottle hanging in her create so she drinks at night and still holds it.
Maybe your create is to big, or maybe you need an expen. Your baby sounds confused. I'm so sorry you are going through this. It is tons of work to potty train but once they are it is well worth it. Chewy is fully potty trained and he was from a pretty young age... There is hope.