RE: when to stop trying
My take on this is a little different. Concentrate less on the instructor and more on the sim. Buy Realflight and practice practice. Learn to fly and land every plane in the sim .Switch up planes and learn the differences. Practice slow fight. ONLY when you can fly and land all of the planes in the sim go out with your instructor. By that time if you can get over the butterflys you will probably not even need a instructor. I taught myself to fly on Realflight without any instruction. My first plane was a Art-Tech P-51 which I tossed into the air at home in a field one night without any one else around. Ive got dozens of flights on it now with only a couple of busted props. My next plane was a GP Giant big stick with a dle30 on it. Which I love to fly.
Regards
Sbdwag