1: Your age should absolutely NOT prevent you from reaching PPL standard within a reasonable period...but your poor co-ordination might.
2: Personally I would have your next couple of hours at a different club or school.... it is just possible that your present instructor is not ideal for your particular needs.
3: Don't give up without a fight......... but IF 2 or more instructors hint or say that you're going to struggle.... keep the remnants of your dignity and £££££££££!
Good Luck anyway, BM