I truly laughed when I envisioned you putting dry Protein powder on your jello---oooououououououo!
The protein would be added to the cold Water when you are MAKING the Jello from scratch! However, I'm not a jello person--so I make sugar free fat free jello instant pudding: Add 2 scoops unflavored whey protein isolate to 2 cups cold skim milk and mix. Add a small 3 oz. package of any flavor jello instant pudding (make sure it says sugar free/fat free), whip it up, and put it in small 1/2 cup containers in the frig. (Makes about four)
I've read in these threads where people also put the unflavored protein in mashed potatoes, oatmeal, etc. but I've only ventured into the pudding. Good luck in your journey!