Hi Nurse_Rena,
welcome to the Apple (user-to-user) Community.
Re: "Unicorn Emoji : attach themselves to my text"
Wondering which Mac, or device you are using,
and
which MacOS or iOS, iPadOS version is installed.
If the Messages app isn't working properly:
Try closing the app,
Eg: How to: Close an app on your iPhone or iPod touch – Apple Support
then restarting the device, and re-opening the app:
Check to see if iMessages is now working as expected.
or
On Mac: Quit the Messages app.
(In Messages, click Messages in top Menu > Quit
Restart the Mac: (Apple Menu > Restart)
Then log back in, and re-open Messages.
Check to see if it is working as expected.
All the best :-)