OneMomentAtATime
Though the WP and I are no longer together, we remain friends and do many activities together.
This is what is keeping you stuck in a pattern of familiar.
I recognize this pattern as I'm living the same reality, without the activities. I'm his Plan B, C, and D. He is constantly in your orbit and ruminating makes it 1000 times worse.
It's very hard to get out of this head space. NONE of what happened is a reflection of you or your value. Absolutely ZERO of it had anything to do with who you are as a person. It's 100% about who HE is as a person.
I'm glad you took nothing from the home and haven't visited there. It's now a tomb to what used to be. Filled with "what might have been" and memories. If you want to be healthy quit being his friend. He has enough friends, you are his comfort blanket. He is familiar with you and no real effort is required to keep you in his orbit.
Throw him off his axis, and for your own health disengage, distance, and then you will have space to heal. He is making empty promises. If he were "always going to be there" then he wouldn't have done what he did, and you wouldn't be having this anguish over a man that choose himself over your peace. My WS says the same thing, and the reality is he would be there in an all out catastrophe, but at what cost? The cost of continuing to allow him to use me for "wife energy" and have less than ideal women as his focus? I've rescued him dozens of times, and it's a very lopsided mostly one way street. I provide and he takes, and I get to watch all the "fun" stuff happen for some other women that did nothing but show up. All of them have been a step down, not up, and the last one is bottom of the barrel, settle or be alone. Many men can't stand to be alone in their own thoughts. I have a plan to end my struggles and remove myself, it will take longer than I want, but it will come to pass.
I completely understand how and why you are worrying about the future. Be as proactive as you can and plan for a future that doesn't depend on anything from him. You've been strong enough so far to survive, now you need to take the next step and end your own suffering. You will adapt to the new reality of taking care of yourself solo. My guess you've been taking care of yourself solo already but can't see it.
You will survive and thrive but it will be an adjustment. Trust yourself, and I know you'll be ok in the long run if you plan for all possible outcomes ahead of time.