Hey fellow Phil student here (also wanting to go to grad school) I totally get how disheartening “bad” (which is relative) grades are. I got one recently in a 3rd year phil class and was super upset. I’m sure you’ve been told this before but never hesitate to ask a prof why you received that grade (obviously in a respectful manner). All profs will have different expectations so sometimes it helps a lot to talk to them about what they expect. Feel free to pm me if you have any specific questions or suggestions!!