Accused of cheating

Because he may be back to his old cheating ways. It's easier to accuse you than to risk having you find out he's back to it. Or maybe he's just paranoid.

Either way, get thee to counseling - either the marital kind, or alone. Get some coping skills or a way to get this junk to stop. He does not trust you and that is lousy for a marriage. It would be a dealbreaker for me, and for a lot of people as well. Decide whether you will put up with it and, if you won't, what your exit strategy will be.

If my spouse went through my phone... that would be the end of the marriage. Period.

Change your passwords. If you think it is worth it, go to marriage counseling, then go to a divorce lawyer.

There is no way that you should put up with this.