Changed my appleID email but now having sync issues both on iPhone and iCloud for windows

Changed my appleID email as I no longer have access but since I did, my iPhone says the iCloud and iMessage accounts are different & it won’t load iCloud messages on the new phone nor will it show my photo in iMessages. additionally the iCloud on my windows wants me to log back in but the Apple ID portion is grayed out and so it tells me my login isn’t valid. I tried to revert to the older email but now it wants me 2 verify w/ a code to update but I cannot as I said above.