a bit insecure

My fella has been avoiding me all week. He dosent really text back as often. And hasn't been calling in to spend anytime with me. I've tried ending the relationship thinking that's the problem. But then he begs me not to and tells me he will change. But he hasn't. His head has been elsewhere even sex isn't the same and he's been avoiding that too. What is wrong with me 😢😭