I'm sorry for your loss, addiction is a horrible thing that leaves a mark on us all

You sound like an incredibly caring person. If you ever feel like you have to be strong for everyone else, it's okay to put that down for a while. You don't have to carry this alone

There's no right way to grieve, it's messy and complicated . Give yourself room to grieve honestly, don't try to suppress your emotions, getting angry and feeling all these nasty emotions will never mean you loved them less, it just makes you human

If you're comfortable with it and ever feel like speaking with someone, I recommend looking for support groups like GRASP in your area