I would end this thread if I were you, OP, get yourself a PAYG phone, one new computer/laptop, and do everything on the advice of family/trusted friends and solicitors.
Also, if I were you, I would be feeling massively insecure and unable to trust my home, car, gadgets, let alone OP.
I see you have DC. Is it feasible to up sticks to a family member's home? You need to leave this house. It's no longer your home, you have no idea what's going on.
I'm thinking of a clean break from him in an environment he has no access to.
Aside from the obvious violation of your physical environment, he has sown the seeds for long term mistrust of people, for not always looking over your shoulder snd second guessing. That would be my grounds of divorce, as I might be able to get over this specific violation. It's the fact he's ruined your ability to trust anyone, and be able to relax in your own home.
Take him to the cleaners. You will need every penny to make a free, secure, comfortable home for you and your DCs.
You poor thing, I am so very sorry that this is happening. It's criminal, legally and morally.