I am so sorry CT, I do understand how hard it is to lose a mentor who helped to shape your life and your career...they are not just bosses or employers but friends and family.
It seems lung problems are going around because my oldest brother in law is in ICU with pneumonia and other lung infections...he is 93 and it does not look great...time is passing and none of us is getting any younger...and those that we love are unfortunately leaving us, in droves...
Although I cannot imagine a world without some of the people that I love the most, cherish and who have shaped me and my world I can understand that they are tired now, have given us all of the tools that I need to continue forward in life and that I need to give them permission to go, in peace.
I find comfort in 'order'. People leaving in the order in which they had arrived on this earth...in warm beds and surrounded by those who love them.
Give all the love that you have to give and never left anything unsaid or un-done...
And then thank God that you had them in your life as long as you did.
It may hurt today but in the long run, it will give comfort and a measure of peace.
I am so sorry for your loss.