Hi and Welcome to 'Ask a Doctor' service .
I have read your question and here is my advice.
Sorry to hear of this sad news, infact
lymphangioleiomyomatosis (LAM) generally effects people of this age female in thirty , this is a disease in which muscles in the lung proliferate extensively to make lot of small
cyst than can rapture and may cause recurrent pnenothoracis.
Regarding the prognosis , the course of the disease is very variable , however the disease slowly progresses over many years.
You have rightly searched according to the literature 50% people are alive at 10 years , 25 percent are alive at 20 years .
Regarding it management , its always a specialist job. it may include inhaler some hormones, or some chemotherapeutic agent like serlolimus.
Lung transplant would be something to be considered at the end. If any avoid smoke ,
vaccination , and avoiding
estrogen are some other things to be considered.
Best of luck
Hopes this clears your mind. I would be happy to answer if your have any thing else to ask in this regards.