I’m in nursing school, stuck in a toxic loop with my ex, and it’s wrecking my mental health

We broke up in May, it’s now August, and I still can’t let go. I’m in nursing school and this is destroying my focus, sleep, and peace of mind. These screenshots are an example first one was Friday and the second one was yesterday Tuesday

He tells me he doesn’t “lust” after me anymore, then turns around and sleeps with me. He’ll say things like “I told you I don’t want to do anything with you” or “I don’t want you talking to me anymore right now” and “move on,” but never blocks me. I can’t keep no contact for more than 9 days. Sometimes when I break it, he’s softer. Other times, he’s mean and cold.

He’s sent me money when I needed it, once said “time will tell,” and then his mood flips again. I feel like he knows I’m stuck and uses it. I’m constantly overthinking, wondering if he’s treating someone else better, and it’s taking a toll on my nervous system.

I’ve gone through months of stopping and restarting, hoping for clarity, but now I’m physically ill from the stress. I just want to wake up and not care anymore. Why is it so hard to walk away when I know he doesn’t want this

and how do I finally stick to no contact for good?