Well, I am a culinary arts instructor and I will tell you that in order to get an F in my class, many, many, many things have to go wrong. Primarily, attendance can be an issue; have you been to every class and/or promptly made-up missed work in a timely manner? Have you been prepared for class AT ALL times? Uniform intact? Tools/work area ready to go 100% of the time? Are you asking questions to demonstrate your level of interest and engagement? Are you competently completing your follow-up/homework, if any?
I am not trying to bash you. Quite the opposite, really. I just want to get an understanding of what you feel went wrong and what YOU can do to improve. Are there bad instructors? Sure! Do students fail? You bet. However, without knowing the specifics, I think the questions I asked above may be good guiding inquiry pieces that you can either answer here or on your own. If nothing else, though, you have to be honest with yourself!
Good luck and please keep us posted.