Why am I never good enough?

I’ve been in a lot of failed relationships. And then I meet a guy, of course. He treats me like no one has ever treated me, I didn’t even know there was such thing as treating a girl so good. We would act like a couple when we were together but never officially said we were. He told me at the beginning he wasn’t sure of what he wanted and it would take time so I just let him be and didn’t pressure him into a relationship or anything. The other day he asked if I loved him and I said yes. He told me he loved me and I believed it. Now he’s calling me up saying he loves me but doesn’t want a relationship. Just when I thought things were great of course they come crashing down. I feel so hurt and I don’t want him to leave. We haven’t decided what we’re going to do right yet. I just don’t understand why I’m never good enough.