I have been in your situation. Massive pile of bollocks, and emotional turmoil. Took me a long time to realise that we needed to split for the sake of the children, instead of continuing with a soul-destroying charade.
He was financially abusive, along with his other failings. I wasn't perfect either, but I took responsibility for everything. He was unfaithful, I was miserable.
Upon separation, he requested joint custody - aka no maintenance. I took him at his word, and provided a fair split of responsibilities. We lived under the same roof for a year while assets were divided. Hell!
On 'my nights', I stayed home and behaved as usual. On 'his nights', I put the children to bed, then I exercised to the point of obsession, stayed at my Mum's/friends' places for some reconnection with myself. I returned early enough to organise the children and prepare for work etc. They had no idea of my absence.
I regained my individuality and remembered who I was.
Upon finally moving to my new home, I relished his absence. The children took it very well (2 and 7), and now appreciate the purpose of the split. He hid all finances, bar property equity. I let him keep it, and maintained my pride.
I am remarried now to a fabulous man. We saw Relate to resolve my crazy boundary issues. We've had lots of personal problems that we've faced head-on. We're a great team.
Ex-H is a lonely, single man with no drive or happiness. He's a ball of resentment. That's his loss. He got cold, hard cash and a cold, empty life.
You won't regret this, you just have to plough through. I hope you have good, supportive people around you who will remind you of your worth.
You never expect this shit to happen, but it is always worth it for the existence of your beautiful children, and the lessons you take from it.
Talk to people who understand. Imagine your future life, and freedom. Just keep going.
There are fabulous things to come!