How do I get my ex back?

Dumper here, dumped my ex last year because I wanted to be "in-charge". Was selfish, egoistic & kinda an asshole.

Fast forward today, over the last year there hasn't been a single day where I haven't thought about my ex, had dreams about them out of the blue and so on.

Did a lot of soul searching & reflection, and proudly i can say i have matured & am not the selfish/egoistic person i was.

Just found out my ex hasn't dated anyone since me & they broke up, and neither did i....

I really wanna get back with them & get things on track but im blocked on social media & my phone number too how should i initiate the conversations?

I'll be seeing them in a couple days at college

TLDR: Being blocked on social media, how do i initiate conversation or talk to my ex after having no contact for a year?