<human>: Can you condense the text into three sentences or less?

I broke up with my girlfriend a few weeks ago. It wasn't sudden, it was something that we had talked about over the last month. She was absolutely devastated though, and completely heart broken. As much as I still care about her and remember all the great times we had, it was something that I needed to do.

When we broke up she said that she loved me more than anyone before, and wouldn't be able to easily get over it.

Knowing that she has struggled with a lifelong battle of depression, I wanted to make sure that she was doing okay by checking in with her friends. To my surprise I find out that she had started dating a heavy drinking and druggy kid she knows and removed all of our pictures together on social media outlets just days after the breakup.

I don't feel good about this. I got to know her very well, and I loved her for a long time, but this, its not right. I am very worried about her.
<bot>: ex-girlfriend with a history of depression seems to be rebounding in a very worrying way. What can/should I do?