i got emotionally involved with an older guy and i feel stuck and regretful

i need an outside perspective because i dont really feel like i can talk to people i know about this, I started talking to an older guy online and at first it felt like just attention and validation i liked it at the time but now i feel really conflicted and honestly regretful about a lot of it

he mostly only texts me now when its sexual and i know deep down he doesnt actually care about me as a person but even knowing that i still feel attached and i still get the urge to text him or check on him I’ve also done and sent things i regret and now i just feel kind of ashamed and stuck between knowing its bad for me and still missing the attention he gave me at first

part of me wants to block him and move on but another part of me keeps hesitating because i dont want to lose him even though i know its not healthy

i guess im asking why is it so hard to let go even when i know its bad

and how do i actually break out of this cycle without going back

please be honest but not mean