Shit I am so so sorry man. My heart breaks for you. I now understand your initial comment fully. In Afrikaans we have a saying, "Spyt kom altyd te laat" which means regret always arrives too late. You know we all make mistakes brother. Some of mine include drug abuse and messing around with prostitutes. Others had to do with wasted opportunity and breaking down people relationships. 33 Years in the making and I still make some big blunders..
Those big if onlies can become such destructive drives in our lives. Chin up man, aim those pointy arrows at the things which try to steal what your boy would have brought you today: immense joy. Because that is your destiny that is your calling. Never doubt your position and royal right to peace, joy and a fulfilled life. It is always at our doorsteps no matter what!