Deborah, sorry to hear about the loss of your father. I don't know that you ever really "get over" the loss, but eventually you will find your center again -- even with the stamping. It just takes a lot of time. I'm sure this being around the 1st anniversary makes it more difficult. Maybe it would help you to break the "unhappy" link between stamping and your dad's passing by thinking about the joy he got in receiving cards you made for him. That way, the mental link becomes more about happy memories, not sad ones.
As for the not-CASE-ing goal, that made me smile. Sometimes I successfully CASE, but it always seems to me that when I try to CASE, I just have the darndest time getting it right. Apparently I am a tad "copy deficient." LOL! I think that the many sketch challenges out there will give you a great tool to transition from CASE everything to "create my own" stamping. Good luck with this goal. I look forward to seeing how your style has developed by the end of the year. You can do this!!