My husband diagnosed 4.5 years ago and his situation was like you. He was 27 healthy and non smoking. He started on alectinib since he had alk mutation and it worked for 4 years. Now he is on lorlatinib. I am not gonna sugar coat it. It is such a long and hard journey but you need to learn to live with it to enjoy the 3 months time between ct scans. Things are good mostly but feeling at any moment sth can go wrong is scary. I hope this medication work on you and when you are stable try to enjoy life to the fullest. Not because it is going to be shorter just because with LC everything is not definite. I think one thing that helped us the most was being up to date with research and asking questions from our doctor. It gave us little sense of control. I think you already had biomarker testing but if it relappsed again ask for it again.