how to activate imessage for your phone number

I have the same issue but it says its verifying my phone number. It was working fine yesterday and then I did the update for my phone and it started using my email address instead of my phone number. Under iMessage-->Send & Receive--> Waiting for activation... that's what is says... not sure why it needs to verify my phone number when it was working yesterday. Is this a glitch with the new update? I email is listed and I removed and added back and it still verifying my phone number has been all morning since my cousin told me she was getting messaged from my email instead of my phone number via text message.

Go to settings > messages > send and receive and then select your phone number.

If you can’t turn on or sign in to iMessage or FaceTime - Apple Support

i cant use my phone number to verify for imessage why