I think what Mach posted is spot on. In terms of why YOU care - IMO It is as simple as ....you Love Him...yep that simple dear.
As you go and grow thru this process you will come to realize that you really can love someone yet not do things with an expectation that the response will be what u so desire. In time you will come to realize that you must let the rope go - you must not enable him. You must let him find his way.
You are doing well and I hope your son feels better. Enjoy the rest of the weekend.
God Bless Eric
"The difficulties of Life are intended to make us BETTER,not bitter". "Fear is a prison, where you are the jailer. FREE YOURSELF!" "Life is usually all about how you handle Plan B." - Jack3Beans