It isn't how it works. Butyou do need propper advice and fairly fast. Do you have people who could child mind for you?
This weekend is too soon for you, from what you post, but give him a date i.e. third weekend in January so you can get some basic advice and then start a financial dialogue.
It does get easier, you will cope but right now one day or one hour at a time is enough.
Tomorrow is the first day of the restof your life. You are in control of your destiny.
You need to gather your strength and list your personal priorities. What do you want? The kids full time or a split that means you could have some time to you/ work?
How long do you have left on your course? It would appear practical for initial financial arrangements to cover you for this period, as no doubt this is your families long term route to stability.
The fact that he's prepared to talk is positive. Keeping dialogue open benefits everyone, especially the children, longterm. It's very important that you learn to focus on your needs not acommodating his. How long he wants to rent is his issue. I'm guessing you need stability to finish your course - a comitment he was no doubt involved in. Focus on you. It's the time to be selfish.
Lots of support to be had here. Its seen me through. Mine were 1 and 3. I'm remarried with another one now and the boys are 9 and 6.