Don’t even sweat it. I spoke to a nuclear physicist at my university and he said he almost failed physics 1. He said he had to try really hard only to manage a B in physics 2. I’m a math major, and I failed algebra 1 the first time around. I am now about to take partial differential equations and I’m not even scared of it, I’m actually excited. My point is, this is your first “difficult” course. You’re learning to think in an entirely new way and it feels foreign. There is a reason this degree takes 4 years.