Why are all my Imessages sending in green even though my Imessage is turned on?

All of a sudden my text messages "couldn't deliver" in blue randomly today and started sending in green. I have my Imessage turned on in settings with my phone number. I tried turning that on and off and nothing worked. I am also unable to join FaceTime and can only send imessages through my computer. I've tried force shutting my phone down and resetting it. I have an IPhone 13 Pro Max with version IOS 17.4.1. Nothing is working. Please help!!