before I see/saw

  1. My mom had told me I should not be afraid before I saw my dentist.
  2. My mom had told me I should not be afraid before I see my dentist.
  3. My mom had told me, " I should not be afraid before I see my dentist."
    Please correct and comment.

My mum told me not to be afraid of my dentist.

‘had’ is not usually required in your sentence. The simple past is fine, more often than not, as the order of events is made very obvious.
The tenses are:
My mom told me I should not be afraid before I saw my dentist.
To improve the sentence further, the phrases could be rearranged for clarity:
Before I saw my dentist my mom told me I should not be afraid.