What a great story!
Glad you persevered.
I was in a situation not too dissimilar... I pledged a local sorority, then called my parents to let them know, and that was how I found out my dad was anti-greek. He tried to convince me to depledge, but I just told him that it was my decision to make and that I would be paying my own dues, and that was that. (I think he was concerned about hazing. I reassured him that I would depledge immediately if I were hazed, but I never was.)
My mom, on the other hand, was very excited that I'd joined a sorority - something she never had a chance to do.