I'm all done, but I can't take my needle out

PLEASE HELP!!! I have finished a very simple knit flower pattern for a headband for my daughter I have come to the last stitch in binding off, but now if I take my needle out it will unravel, what do I need to do?

It won’t unravel that easily. Pull on the loop to make it larger, then take your needle out. Cut the yarn and either pull the loop completely out, or thread the tail into the loop and tighten it up.