R.J.
Honey, you need your own lawyer. It is honestly not fair to EITHER of you to simply have one, even if you agree on every last teensy detail, will you next year?
Divorces are a sticky and tricky business, and the law is even more tricky (hence why people go to school to become lawyers in the first place).
Legally speaking, 5 years is not a long marriage. You may actually not be entitled to alimony. Is the house paid off? Who gets it? Do you know that it's considered an asset and not a debt (what it can sell for, not how much the monthly payments are or how much is left to pay off)...and that if you DO qualify for alimony but get the house that can cancel out the alimony? Even mean that YOU need to pay HIM to make the formula come out "even". Do you have a degree? Did you know that part of the divorce can (but not always) include be the payment of 4 years of school? Who came into the marriage with what monies? What was aquired during the marriage, and upon whose "balance sheet" does it get allotted? Who claims which children as dependents on tax returns? If you live in two different school zones, which school do the children go to? Who is responsible for paying how much for education expenses & or private school? (Private schools look at the income from BOTH parents, divorced or married, btw).
These are all legal questions (and just the tip of the iceberg) that have to be addressed and answered in the divorce and parenting plan. You very very desperately need your own lawyer to help you through these NOW, and a year from now when some crisis pops up. If your ex gets offered a job in london and wants to take the kids with him, do you call the lawyer that just served you and the court notice of intent? No way!!! What if your mum in SF (obviously, I don't know your mum, much less that she might live in SF) gets sick, and you want to take the kids with you to take care of her for a month. Who do you call & where do you file? What if YOU get offered a job in London? You need your own go-to person. Someone who's sole interest is you. It's understandable that you still feel like a couple in your mind or reactions. But you're not. You are an individual who's life is shortly going to become very very different from your ex's.
A judge, btw, is not likely to look favorably on the argument of "the plan was"...the plan was that the two of you were married. "The plan" has now officially changed.
Please know that I'm neither trying to be harsh, or advocating you stay with your husband. FAR FROM! In the most amicable of divorces all of these things all have to be answered and dealt with. From the way your soon-to-be-ex has already treated you, and by what he as said about taking the kids and having them in daycare so you can't have them...I do NOT suspect this is going to be "the most amicable" of divorces. You don't need to get a lawyer to go for the jugular, but you need to get a lawyer to make sure no one goes for yours.
Best of Luck sweetie, these things suck.