Have you taken legal advice? Maybe try the Wiki helpline (number top right). I thought after a short marriage with no children between you that you both take out what you brought in. Get some advice, never believe what a stbx tells you their solicitor says they should get, get your own advice.
Hi. Sorry to read what's happened, but never regret being a good guy and a nice person!
Listen to your lawyer and check things out on here. Call the helpline if you need to discuss things before making decisions.
I felt just the way you describe when my world fell apart. I'm sure most wikis would say they've experienced some very dark days, but wiki friends will help keep you focused and grounded. Nothing lasts for ever and this awful time will pass. Things will get better - sorry, but it will take time before you'll feel better. The days seem to be full of worrying thoughts and sleep evades you but it will slowly, a day at a time get better.
It says a lot about the kind of person you are that you took on the children and cared for them, but of course you feel a greater loss now.
Life will pick up again when the legal situation is dealt with. One day, you will find the peace you deserve.