Oh OP, sadly your post brings back so many memories for me. I had an argument with my ex once because I accidentally pushed out my chair and brushed some guys leg in a restaurant and said sorry . . . This was apparently me flirting and disrespecting him! It was early in our relationship and should have been a bigger warning to me.
Things got much worse - I had a kid with him and his behaviour escalated. His emotional abuse became physical and eventually I started to find help. ( I had been planning on leaving and talking to women's aid but leaving happened earlier than planned as neighbours called police on hearing an argument/assault).
Your husband is abusive - emotionally abusive. Stay calm and start to plan to leave- women's aid can possibly work out benefits and emergency housing but for your childrens sake please just leave.
Survival advice -
Fake apologize - buy time to plan. He won't be able to help himself with cycle of nice and explosions over nonsense but each time say sorry and work on planning your departure, financial evidence etc.
Record everything - I emailed it to myself so that kept the dates for me and didn't worry about a diary around the house.
Tell people - talk to doctor, talk to health visitor, sons school. They will be sensitive. Social services may get involved (didn't with me in end as I had a restraining order so dd was safe) but when I first started talking to doctor he didn't contact them that I know of.
Do you work? I also told my boss - not quite full story just that things where difficult at home and I ended up crying and he joined the dots and was very supportive of putting things in place to make work less stressful.
Talk to your brother, can he come get you? Can family come and stay . . . They may see his mask slip.
Call women's aid - they are amazing. Always busy so don't be disheartened if you don't get an answer just leave a message and they will get back to you. Women's aid may be able to place you and your kids in a shelter. Take it if offered - I always thought my situation wasn't so bad that I needed this but in hindsight I wish I had went to a shelter before things got physical.
There is also a free legal advice line- rights of women. Again hard to get an answer but keep trying. The lawyers that volunteer give great advice.
Also - and this may require some bravery, can you call into police station? Talk to a community officer. I have possibly missed your age in your post but is it possible that your husband has a history of abusive behaviour before you met? Under Claire's law you can request to know if there is anything on his record to do with dv. (For my ex there was - I could have went and found this out had I known about Claire's law when things first felt dark!)
Be calm, be safe, have a bag ready in case you need to leave quickly (passports/birth certificates/money/medications etc) and get planning. Do not tell him you have even thought about leaving . . . Tell him when safely out!
Also - if he is wanting to go for a week, let him go as his presence may spoil the birthday otherwise! This also gives you a break from him!