Is ghosting normal?

I was in a relationship for 4 years. Things were good until one day he left me, ghosting me. He stopped answering my calls, texts, and even stopped meeting me. He said that he needed space and never returned. I had gone through a lot and couldn't focus on anything. He destroyed my mental health. I tried to contact him every day. At least I deserve an explanation/closure for the time and energy 1 put into him. This is not right. It happened a few years ago, and now i have moved on, but I have trust issues. I can't trust anyone. (Anyway, he is married now.) How can I overcome that? And why can't people give clarity and make others' lives miserable?