Sorry to hear the tragic news, but you certainly seem to be pretty self-aware. That's important. I'm betting you're a pretty talented guy and probably heard others tell you so along the way...maybe you figured "things would just work out" and now you've found yourself at a crossroads at age 26? Maybe you're seeing old friends get married, or seeing others in your peer group with fancy jobs and real money. You might be wondering where you went wrong? You might feel like everyone else has direction...but you're feeling lost.
Well, don't worry, buddy. Lots of us have been there and survived to tell the tale. Remember that life is not a race, it's an experience. And nobody's keeping score (even though it feels like it sometimes). Once you can let that go, nothing can stop you.
The only thing that will slow you down and do more damage is abusing alcohol and drugs. I was around your age when I started a 10-year spiral that nearly killed me. I'm pretty happy I quit, and I think you will be too. Don't put the cart before the horse. Ever see someone try and fly an airplane before they know how to drive a car? There's nothing wrong with dreaming big, but you've got to put in the work on the little things. You've proven that you can survive some pretty tough challenges - I'm sure you're more than qualified and capable to handle quitting drugs and booze. I hope you find some support here!