Welcome to PC!

So the questions I would ask you are: did your mother place a lot of importance on physical beauty or her own appearance? Or your father? Were you ever praised as a child for your inner qualities or your accomplishments?

If you did not receive much validation as a child, you may have developed the need to be validated in other ways, ie, physically.

That is my most educated guess.

I hope you are seeing a professional about this now? What you will need to work on is developing self-validation tactics for your inner qualities, and developing greater self-love from within. Beauty fades, so relying on this alone for validation and also sexual arousal will wear thin.

((((hugs))))