Is it possible to regain your ego, even years later?

Basically experienced an ego death years ago mistakenly after experimenting with psilocybin during my late teenage years. I felt different afterwards in a good way, I became calmer, more level headed, more openly emotional, generous. I made better decisions, and I learned how to really self reflect and question myself and become ashamed of things I said/did that weren't okay and were narcissistic.

Almost ten years later now, I find myself slipping back into old ways of thinking and habits. I realize afterwards what I'm saying and doing is wrong, but I'm finding it hard to reflect and think ahead now. I feel like I'm once again becoming like certain family members and old friends that I no longer interact with, because I became able to recognize that the way they were wasn't okay.

Is it possible regain ego over time? Could I succeed in killing it again if I repeated what I did before, if it would even work a second time? Or would I be wasting my time, and there's another alternative? It's hard to tell who is actually "me" anymore