Am I getting worried over nothing?

[? Mark]

Long story short--I was contacted by an ex who broke up with me about 5 months ago. It was out of the blue, and she sent me a text asking for my forgiveness and wanted to know if we could be friends. During the course of that conversation, I found out she just got out of the hospital since she ODed on alcohol and other drugs. I knew she had a drinking problem when we dated, but nothing this serious. During the relationship, she didn't treat me right and was rather nasty to me (the relationship was mostly about her, and what I wasn't doing right). We haven't text a whole lot, only a few times so I'm not sure what she wants to do with this whole things.

One of the things that she really hated was me being a worry wort. It drove her nuts. I haven't heard from her in 4 days, and she hasn't been on Facebook either. I sent her a text on Tuesday and she stopped replying all of a sudden and I figured it was because of work or something else, so, I didn't panic. Being days later, and no word from her, I want to text her, but, in the past she has been rather nasty to me, saying things like "If I don't reply to you, it's because I'm busy, " etc. Should I just wait for her? I'm worried she has become alcoholic again, or, worse yet, she may be in trouble.