Welcome to Psych Central, dewdew. I don't think I have much in the way of advice for you with regard to your concerns. However I noticed no one had replied to your post. So I thought I would. Based on what you wrote it sounds as though you're having difficulty knowing how to deal with your friend's anger. So here are links to 3 articles, from Psych Central's archives, that offer tips for dealing with other people's anger:

How to Switch Off an Angry Person

How to Defuse Anger in Ourselves & Others

How to Respond to Angry People | Anger Management

You also mentioned your friend has bulimia & it sounds as though you're having difficulty knowing when & how to help. So here are links to 3 articles that talk about being of help to someone who has an eating disorder plus 1 that talks about situations where a person has both bipolar disorder & bulimia:

Helping A Friend With Body Image Or Eating Issues

Eating Disorders Awareness Week: Helping Someone Who Is Struggling

https://blogs.psychcentral.com/weigh...ve-been-there/

https://blogs.psychcentral.com/bipol...meets-bulimia/

I hope you find PC to be of benefit.