Now my instructor has no confidence in me and has suggested I am not really cut out for flying if I can't get the basics right!
I think first of all you need a new instructor, maybe even a new school. It's possibility that the truth is that your instructor can't get the basics right and is not cut out for instruction! You need to analyse the situation thouroughly. Is your instructor so bad that he would put you through a GFT before you are ready? Lots of us go through doubts about our abilities especially when every landing seems to go pear shaped. Go get a second opinion!
Keep smiling and try to relax.