imessages bug

I have tried every solution i can find on the internet regarding the imessages not working on my device anymore.

When i took out my SIM card the error occurred and i’m unable to use with my phone number.

When i open my Apple id, my number is not displayed and when i try to input my number it says “the number is already used in another account”, i don’t have another apple device.

When i go to imessages in settings my phone number is displayed there, i can click it but nothing happens..

Anyone got a clue, what’s going on?