Hi Xenops,
It is not the French "r" that you are not pronouncing well but the pronunciation of the entire word. Your "r" is good. Sometimes you are incorrectly pronouncing/reading the word in French and this is what makes it incorrect.
Tomorrow from 9am to 3pm I am busy with a group of High School students and teaching classes. I will be done at 3pm. If you would like to come at 3pm in my office yes you are welcomed.
Well, this is confusing. All I can deduce from this is that I need to work on all my sounds, as Ingaræð and Ani have said.
Thank you everyone that has responded, and have had patience with me: I confess that I've had a hard week, and the thought of still doing poorly at pronunciation was the final needle to prick me. I'm frustrated because I've been working on pronunciation since August, and I thought I would get a handle on it by now, especially since I hear about people that conquer the pronunciation at early as in the first month.