Well done! Ignore the ones telling you you didn't need to do this, or that it's stalking. I'd bet they have a hidden agenda. Flick them all into the corner.
You've accessed your intellect and your rage and focussed them together on finding the truth, which will help you find closure.
Now you have the facts, see a solicitor and financial advisor first to gather essential information about your children's, money and property etc rights.
I'd be inclined to sweep half of all joint account contents into my own account immediately before the conversation with him.
Asking before presenting the evidence will prompt and expose lying, evasiveness, gaslighting - the real personality behind the mask.
Be prepared for denials, accusations of 'you're crazy, you're imagining things, you know what you're like.' They're very common.
It will help you with your resolve as you uncover who he really is and what he really thinks of you.
And you have the information that will brush excuses aside.
Decide what you want to happen then tell him what is going to happen, rather than hanging on waiting for him to decide.
An assertive, proactive approach will always be better than passivity.
Be prepared for a panic attempt to scrabble things back to normal. Apologies, tears, promises, it was a mistake, I'll do better. Mr Nice is a tactic that you may fall for, but it's just the mask temporarily back on again.
When he realises the game's up, be prepared for 'well if you hadn't' (insert bullshit here) I'd never have (insert further bullshit here)...' attempts to DARVO. No. He chose to do this.
Mr Nasty will probably kick in, as so many women here discover, and having your legal and financial team already in place will support you.
You'll need your family and friends around you, because Mr Sneaky may be in play too, undermining and spreading lies about you. A relative's ex did his, messaging us all in turn with lies.
All the very best to you.