You are in an interesting situation Sir. My best advice is to have your instructor spend a little one-on-one time with you before or after class do to a blind mirror mold. Mirror molding is usually done by looking in the mirror to make sure you are in the right position, and then repeating the move until you have muscle memory. Since you can't do this, I recommend the instructor put you into the ideal position for a technique, such as knife hand guarding block for example. You will need to hold it still for a long time, either from an L-stand or Junbi, and then attempt to execute the exact same block again without moving anywhere including intermediate hand positions. The instructor could then reposition you back into the correct position. After a number of times, you will start to build the muscle memory by feeling rather than by sight. Just an idea. Best of luck, I hope you keep going!! Taekwon!