You are clearly still emotionally under his controlling thumb. He sounds likely abusive, especially as you say he plays the part of perfect spring daddy to to outside world.
Please do some independent research on post separation communication strategies. No you don’t have to contact him daily & let him know everything. Write it in the contact book so When he picks the kids up he knows if one is sick or needs medication etc.
If they go to a docs appointment I would send a brief text outlining the outcome of their appointment.
You want to avoid daily communication or any communication that turns into a back & forth conversation.
You sound terrified of his anger. But you must be strong & let him be angry. Turn the phone off. Go out. Do not wait around for him until 2pm because he cancelled plans at 9am. He is clearly trying to control your life from afar. He will do anything to make your new life difficult. You should not be changing your plans to accomodate or prevent his angry abusive outburst.
Keep a diary & supportive texts to show he has failed to turn up at agreed times. I also agree to meet in a public place.
Also agree do not reschedule visitation - if he isn’t there he misses out.
Next he will likely try to regain control over you by keeping the kids longer to scare you - what you must do when this happens is appear to be relieved & elated that he wants to spend more time with them, so you can go out / do weekly hobby etc. Once he knows you like the free time he will drop them back sooner.
Basically you need to be smart, cunning & practice reverse psychology on him.
You can get a burner phone just for him, leave it in a drawer & check it mid-week. Don’t be messaging him back daily.
You were very strong to leave him - but controlling & abusive men only escalate or change tactics, which is what he is doing here. Using visitation to control you.