It's about to be 3 weeks since my ex left because of me 'disrespecting' her. I haven't been affected the first two and a half weeks but it's starting to hit hard

I've started going to the gym, speaking to more girls, learning a new language and focusing on my career changes. I've been more social with my friends and family but now it's hit me and I feel like I have a mental block. It's not to do with hopelessness cos she's a girl who's always been chased by guys and even jokes about having me 'wrapped around her finger' and chases me when she sees I don't contact her in any form

What do I do to move on?