Bones, everything you say is about him and his feelings. It's like you are at his mercy. This needs to change. You need to get a new mindset.
You must forget about what he might or might not feel or want and focus only on you and what you want.
It sounds as though you feel you have no control over what happens, you're at his mercy, waiting in limbo for him to decide.
Wrong. You can and must work out what you want here. No way should he influence your decision. You say the trust is gone, you'd always have doubts...so work out if anything he could do could repair the damage. If you know in your heart that it's over, you must have courage in your conviction and work on detaching and your future. You need strength to trust yourself, so that what he wants bounces off you, not affecting your decision at all.
It's a horrible situation. But you must focus on you, not him. You can simply detach, divorce and move on, saying 'it's too late, we're done' if he tries to talk. Just because he might want to talk doesn't mean that you have to. Just because he might have second thoughts doesn't mean you are having them.
Stop overthinking his phone usage, and his involvement with OW. It's eating you up and deflecting time which would be better spent on thinking about the future you want. He could lose you through all this, but that's his fault and his alone. Don't be reactive any more, be proactive. First step, decide once and for all what you want. x