My ex is starting to fall for someone else and I have no idea how to even handle it

its been a year since the breakup, yet I don't even know how to feel knowing that he's finally starting to move onto someone new. He was always so avoidant, when we first started dating he used to be so attracted and texted me on the daily. he was so affectionate, but then went so silent. I hate even thinking they're going onto someone else. It hurts so much even if its been a year...