Yeah, that really does seem stress inducing when people don't clearly say what they want. The only way to really know is to be honest on how you are scared about them not wanting to be friends anymore. But from what your friend said, if you were actually a bad influence, wouldn't they leave already?
I know I am doing the annoying therapist look from a different perspective talk. But normally when people post things on social media platforms, it isn't the whole story. I think the post isn't directed to you, but to other people. It's easier to say friends than have to hint at who and start drama.
If this is really out of character for them, I would be a little concerned. Randomly leaving close friends isn't something that people just wake up and do. I would keep a eye on them to see if they are struggling.
But I understand that even with all the counter arguments in the world, the worry of what ifs could still be there. And that is okay. Just try not to act on them because they can make people do very dumb stuff, trust me, I may or may not have spammed a friend with melodramatic apologies because they didn't show up, turns out they were just really sick that day.
I thought about what I wanted at that point in time, not thinking about what my friend wanted. Many instances like that eventually ruined the friendship. I didn't give them the space they needed, making them more distant and in turn, me more clingy. But don't let my story discourage you.
Perhaps let your friend know that you will support them on working on themselves. Friendship doesn't have to mean interacting or talking everyday, it can also mean just understanding the other person's needs. I wish I personally would have known that in the past.