The Worst Feeling Ever
There are probably many different ones but the one that comes to mind is when your friend feels betrayed by you. If it was just an acquaintance you might feel a little something but if it is your “best” or like a lifetime friend it can really hurt.
Especially when you had no idea you were doing anything that would hurt them or could even be associated with that concept.
After whatever the situation that arises happened and you can obviously see the distrust that person has for you, if they are a good friend, you wish and pray that you can make that feeling go away. Let them know that you are always there for them and that you do have their back no matter what