I have the same issue with my nail on one side so I'm eager to hear others' responses.

I rarely use a pick now because I've become so accustomed to using my fingers. After watching some of Caren's song tutorials on here, I've started adopting her way of strumming which is to use more than one finger (or at least it appears so). She also has a "Better Strumming" tutorial that is really good and I think that goes into what fingers to use. I just watched that the other day and she also shows you how to kinda roll your wrist when you do the upstrokes.