I've heard of 'thought insertion' where a person experiences someone else's thoughts in their own mind.
What about a person who experiences emotions that aren't theirs? I can't find anything called 'emotion insertion' or anything.
An example: In reaction to an event a person feels both despair and relief simultaneously. They recognise the relief as being their genuine and appropriate emotion. The despair is illogical and confusing and transmitted from another source outside of them.