Pure Unflavored Protein

Ok so my surgery is still 5 weeks out, but my Protein supplies arrived yesterday so I thought I would start trying them to see what I like and what I didn't like. This morning I decided to add some unflavored protein to my coffee. Well, I had already added it when I then read the instructions that it is supposed to be added to a cool liquid and dissolved before adding to hot liquids...So I tried damage control and pulled out the Magic Bullet to blend it, after pouring it through a strainer. I thought, this isn't bad. And then I got to the bottom of the coffee w/ grit and it literially made me vomit. At first I just thought it was a "juicy burb" but then I ran to the toilet and was physically sick.

Has anyone used Pure Unflavored Protein before? If I dissolve it in cold liquid first, will it take away the gritty taste? I am nervous to try it again and just need some reassurance that just mixed it wrong.