First you need to make sure not to beat yourself up for having codependent tendencies. Some of the nicest kindest people have codependent tendencies.

Truth is often we develop this behavior when a parent has issues and everyone picks up the pieces the problem parent fails to do. This is often what happens in homes where there is alcoholism or everyone is expected to work around either one parents or both parents issues in order to maintain some kind of structure or sense of peace.

This can create feelings of failure if one fails to service the needs of the problem parent. Codependency is learning to self sacrifice to constantly meet the needs of others. It’s also allowing ones self to feel fault if the other person is not happy or content.

From what you have shared of your relationship you have some very strong codependent patterns you have been practicing for quite some time now. Setting boundaries and saying no is not going to go over very well. You have become a major crutch.