Just need advice on how to say sorry..

I am sure ill get judged after this since people can be harsh on here but just want advice.. So I've been married almost 2 years to my hubby.. he has 2 girls (6 And 8) I have a 5 year old boy and I'm due next week.. he has to go out of state to get a certification for work(hes an engineer) hell be gone 4 days.. So ill have a newborn, and the 3 older kids.. so im like okay, no biggy its 4 days.. he came home last night and said his boss wants him to go the week before to get a diff training.. So that a customer will order parts from there. his boss is an ass.. always rude to everyone (even my brother who works there) my husband is a hard worker the CEO loves him, he gets paid very well..but he is scared to tell his boss he doesn't wanna be gone almost 2 weeks in a row.. I started crying (hormones) saying how can I handle all 4.. with a newborn ..tell your boss your not doin the second class until.beginning of next year. we fought a bit.. today I'm thinking he stood by me through nursing school.. who am I to hold him.back?? I'm an asshole. he told his boss no and he said it's because he doesn't wanna go he said itll be to much. now I'm, what sorry.. I was in the wrong. what can I do to make it up? I already said sorry he said it's fine but i wanna do something special