A crazy weekend it has been. Need advise on how I did, and please guide me wherever I may have made a mistake

H was either depressed or angry as usual.

Convo 1:

H - D 7 months' day care had made something for father's dad and you had left it in garage.
I - Yes, they made XXX, D3 was playing with it, I didnt find it initially, when I did I hung it u[ on the wall
H- When these things happen you need to let me know since it is for me
I - You are correct, I should have looked and brought it in the same day.

Convo 2:
H - we need to discuss finances and custody soon. You have been stone walling me
I - These are hard topics for me, I understand it is important we will discuss in some time
H - I am moving out in a month
I - Yes there is a month more, so we will sort it out
H - Stop f*ing stone walling me, you think its hard for you? I am the one who has to move out, who will lose money and home
. I will also have to convince D3 the new place will be her home also. You have it all easy just staying back here.
I - I understand this is hard for you, I can only imagine the hurt you must be going through but they are difficult topics.
H very defensive acts as if his head will explode and starts swearing so I just gathered the kids and left the room saying I cannot stay with kids if he continues swearing.

Convo 3-
We started discussing finances and it got ugly. The first ever real argument since BD I think. I insisted whatever money
we have need to be put into a college plan for children
He wants to do this as a monthly committment, with only some saved up front and I did not budge. He said financially its not pragmatic, I agreed but I kept repeating all I need at this time is the children's future secured.
Lot of yelling on his side, I tried to keep calm but broke down saying I cannot move forward if I have not sorted out their future expenses.
He said you act as if I am abandoning them, I said I understand he will be always there for them but putting something in future will be for 2nd child,
at least one child's college funds should be saved right away. He said I am determined to leave him a pauper, so I asked him would my condition not be the same?
He said you f*ed my life for 15 years and you are hell bent on doing it for 15 more years. I knew you were going to make this difficult, I am warning you dont make it ugly

This was the first ever discussion we had about finances, custody has not even come up.
Without standing my ground, I do not know how to be practical here. I might have failed at validating and DB here, H definitely is crazy angry right now at me.

How do you DB in such circumstances? At one point he said, I would have understood if you asked money for yourself, but you are asking it for Ds and there is at least 15 more years for it.
I read sitches where these discussions are peaceful, I am not sure how the LBSs in those case manage it. For the last 6 months I had not provided him new material to get angry, he was ruminating in the past. Today I definitely did, but if I cannot save this MR I need to know that I saved my Ds future

Future convos regarding finances and custody will be worse, how should I proceed? Please help!! Today I feel I took 100 steps back. It seemed like he has gone so far away, its hard to find the warm real him inside this new person.