Hi unhappy
I feel really sorry for you. I just can't imagine how much you may have gone through due to your height. Although I haven't done any CLL, 20cm seems too much for you or anyone. But, 12-14cm could be possible since there are some people who did two surgeries. You can do 6-7 cm tibias. Once you recover, you may consider 7-8 cm femurs. But CLL is extremely difficult and long process to recover, not to mention that it needs a lot of money.
If I were you, I will probably still choose CLL, although I know my max could be 165 or so.
Anyway, it is a tough decision. Good luck, unhappy. Hope you can find peace in your heart someday.