It appears that you are on the right track! You have committed to losing weight by watching your carb intake and you have made drastic life style changes to get the exercise that this requires. You are aware of the problems with the combination of injecting wrong and using the wrong needles.
I personally feel that if you continue to get your exercise, watch your carb intake and inject your insulin as directed by your physician the A1c numbers will quickly get better. I feel that tight control is the key to doing this as well.
It is difficult to lose weight on insulin, but
not impossible. You may want to take a look at this
website. Have you given any consideration to watching your caloric intake? A nutritionist may be able to help you implement the suggested 40-30-30 plan. I hope that this information helps in some way.