why is it so hard to let go?

my son's dad is so wishy washy....when we were together it was always something happening smh n then he wanted to grt married but was so distant with me n communication was off n sex was barely happening..so I ended it this was n Jan..fast forward we got back together a couple times broke up.argued.fought.blocked on social media..just been through so much bs since Jan...n currently we are broke up been about 2wks now cuz he says hes just not ready for a relationship right now(a whole child.13mnth relationship.use to live together- later ) but he keeps telling me he loves me(he always says it first).initiates kisses.weve had sex once since the break up.but he's moving to another state next month for work supposedly..anywho I keep telling myself stop calling him.dont text him.dont respond just leave it be but I always find myself calling him n begging him to talk to me like I know he doesnt want a relationship so he doesn't feel guilty or accountability for his fuckups anymore but I just want to move on N let go but no matter how hard I pray I keep texting n calling.n I'd be cool with everything if he didn't say he love me n don't plan on being with another woman n wanna continue to work on US even after he moves yet ignores my calls n text most of the day.doesnt spend any quality time with me..i don't get any sex like I want n i know he's still full of his usual bs smh