Bummer situation Mario...truly.........To much of the unknown exists everyday and adding in some more can be way too much sometimes and lead to the way you feel now.
I am not making light or trivial when I say that Lenny had it right when he said: "There is only what is; what should be never existed."
If we look at the things we do and do not do every day, as long as we are doing our best at the time, we can do no better......and that is "what is." Second guessing in hindsight is not nearly as great a learning experience as we want to believe as in the present we are (at least most of us) doing the best we can with what we have. What is is what is......and it stands alone. What should be will drive you crazy as it has no basis in reality and can be anything we throw in.
There are thousands of things you could have done but if you are doing and did your best along the way, then those thousand things are academic as they do not represent what is or what was and you'll be forever in a guilt fed depression over what you probably could never have done.
You're a good man, a kind man, a thoughtful and introspective man, a loving man, and above all, a gentle man. Don't let the often and generally impossible possibilities of the past take you down. There is only waht is and what should be never existed.