trying to put a square peg in a round hole

Trying to put a square peg in a round hole is a figurative phrase where someone does not belong in a particular situation or is very uncomfortable in a certain place because they dont fit in very well. As a square peg does not fit into a round hole, this person is trying to combine two things which do not go together or fit with each other. Figuratively, it usually refers to a person being in a place they feel they dont fit in.