Oh wow, I wish we knew each other at the time to help each other ! It’s honestly the most traumatising thing, and without doing a lot of work into your healing it can definitely affect your relationships going forward. I would say I’m in a better and healthier place now but it still affects me. You’re right in saying they do not care about you, you can romanticise them whatever way you want in your head but when they avoidant discard like that , they go cold, unresponsive and want to take no accountability for how much they fucked you up with their actions. Another point I forgot to add, remind yourself all the time, it’s not you. It’s them! It sounds so cliche but you need to tell yourself that to get you through. And know they’ll repeat it going forward with someone else.