He disappeared on me....HELP!!

My ex (dated for just over a year) disappeared on me for nearly a month. I had messaged him with "We need to talk" because I wanted to introduce him to my parents. But he messaged me back with just a "Hi" and no explanation as to where he went to for all those 3 weeks and a bit. So I disappeared on him as well (it has been 11 months since I last contacted him). Next month will make it a year since I decided to move on with my life...

I lost my V card to this man and I thought I would spend the rest of my life with him too but he still mistreated me and disrespected me. Do y'all think me disappearing on him was a good idea or was I too selfish?

Last time I checked his Facebook, he seemed depressed…posting depressing posts about "not taking people for granted" etc.

I sometimes still cry myself to sleep at night, just thinking of what he put me through. It was horrible! I still don't know why I think of him when I don't want anything to do with him! Anyways, I've met another guy (lets name him Z) now and he has asked me out but I'm too scared to let anyone back in just yet. Z and I both went through the same things last year, we were both disrespected by our then partners whom we thought were always gonna be there...

He understands me so much but I feel so heartless nowadays that I just don't want my heart broken and I keep pushing him away. I see that he's patient and cares about me but he lives in a different country☹

What do y'all think? Should I give Z a chance and/or contact my ex to get closure? I really need help...my heart still hurts alot and it's not a nice feeling. Need realistic and honest advice please!!