I went thru something like this with my now 18 yr old girl. We were so close especially after the divorce from my first wife( age 10) but then she got older and needed her mother more. I took it hard but I kid of understood. Our relationship changed but I was still the most important male in her life. I just made sure she remained a daddy's girl and when she dated boys that I was the prototype she compared them to. Even now at 18 its important to her that I like the boys she dates and so far she hasn't gone crazy. But then again she just started college but still lives with mom so there is some control still.