Your letter greatly concerns me, because I know from experience how hard it is to convince someone they are headed for disaster -- when they're absolutely convinced they aren't. I'm afraid this is your situation.
Why do I say this? One reason is because any "peace" you get from drugs is only temporary, and will last only until the next pill. In fact, the "peace" you are experiencing isn't real peace; it's only an illusion (whether you believe me or not). Instead of solving your problems, you are at best only escaping from them -- and eventually they'll catch up with you. Even worse, in time you risk destroying both your mind and body.
On the other hand, true peace -- the kind of peace God offers us -- gives us strength to confront our problems. It also helps us endure life's storms with strength and courage. This is the kind of peace Jesus offers us -- and it comes from knowing we are in God's hands, and He will be with us every step of the way. When we put our faith and trust in Christ, "the peace of God . . . will guard your hearts and your minds in Christ Jesus" (Philippians 4:7).
Don't be like someone calmly floating down a quiet river -- only to discover after it's too late that it becomes a roaring waterfall. Instead, turn to Christ for the forgiveness and new life you need, and put your life into His hands. He alone can give you the lasting peace you seek. His promise is for you: "Peace I leave with you; my peace I give you" (John 14:27).