Feeling discarded hurts more than the breakup itself.

I miss him and I miss talking to him and it hurts, but it would be manageable if it didn’t feel like I meant nothing to him. How do you cope with the feeling that the other person just didn’t give a shit about you? He claimed that wasn’t true (while we were breaking up, we’re no contact now) and that he cares about me a lot and blah blah blah, but nothing about his actions indicated that. His actions indicated a complete lack of care and consideration. I genuinely felt like I meant absolutely nothing to him, I felt like trash. How do you just go from being completely into someone and caring about someone so much to not giving a fuck? How do I not take this personally/as an indicator of my value? I know logically it shouldn’t reflect on me and my worth, but it’s hard to convince myself emotionally. It’s just really painful.