To ask if I’ve been blocked?

[Redreindeertoy]

I’ve just gone to message a friend on Facebook, it immediately said ‘couldn’t send’ and it won’t let me re-send. This friend only messaged me last weekend, everything was fine.

She’s not appearing in my friend’s list and her profile doesn’t come up when I search her name but when I go into messenger, our chat and her profile picture is visible?

I’m now sitting here thinking 😳😳 have I been blocked?!

Sounds more like they deactivated their Facebook. You can do this temporarily and it still gives you access to messenger, in some cases, and in some cases not

If you had been blocked, messenger would be blocked too.
I'm guessing they have deactivated their account.