Having issues with iMessage on my iPhone. My iMessage is turned on and it still doesn’t work. Help!!

Started yesterday and I can’t send any. It’s shows me receiving iMessages but when I send them back to iPhone users it acts like it is sending and then because I have sms messages turned on too. It will send it as a text message. I’ve tried turning everything off and on again updating phone to current apple updated version for my phone and still nothing. I’ve turned off wifi and and back on. Turned off cellular and back on. Still not working. Any ideas or suggestions?? Thank you