Welcome to SR, phoebe...
My mom is also an addict, and I have found answers to the same sorts of questions you've been asking in
Al-Anon. I've come to understand that I have been affected by the disease of addiction in those around me, and Al-Anon has helped me learn to heal from those effects and to live a much happier life.
Here's a link to the
Friends & Families thread that was mentioned, as well as a link to the
Adult Children thread. You'll find lots of supportive people there who have similar issues to what you've described.
I wish you peace...