Jim, I'm sorry to go back to this, I hope you don't mind.
I know today is the five year anniversary of Tim's passing and I just wanted you to know I'm thinking of you my friend
Although everyone's situation is unique, I can empathise deeply with your pain. I too have lost many friends to the disease of addiction, and struggled with it myself over the years. As you know, I lost my brother to a heroin overdose in March, so this hits very close to home.
I hope your visit with Tim today brings you a bit of peace, and just know that there's nothing you could have done differently to change what happened. You were obviously a great friend to Tim and brought him much happiness during his life, so try to take some solace in that and not dwell on the "what-ifs". I know it's easier said than done, and I still struggle to practice what I'm preaching here, so take that for what it's worth.
Hang in there bud.