*hugs*
My fiancee & I just lost a friend last week to a heroin od so I understand your pain.
I'm trying my best to cope, focusing on other things instead. Best not to dwell, just think of the good times & all the laughs you shared, mourn but don't let it take over your life. I'm a firm believer (thanks mum) that while they're no longer physically here, they're always with us. An idea expressed by everyone at the wake, we tried to remember the fun times, his "going out song" was 'The Final Countdown' which he would've loved & we joked that he was standing around getting angry that he couldn't have a beer haha.
They're in a better place & they've served their purpose here in our physical world.
I hope you get through this, if you need someone there are helplines and all of us here on BL!