Yeah, I did it earlier, the switch doesn't even seem to work, when I slide it, it flicks back so I have to press it then it says "waiting for activation" or something and then I sign in to my Apple ID and nothing happens
What switch? If you do a hard reset, you don't slide anything.
Is iMessage not working for anyone else?
Yes. The post above you. Turn off iMessage, do a hard reset, and then turn iMessage back on.