Straight A student getting a B.

Title says it all. I didn’t do very well on the first exam and it’s no ones fault but mine. I think I’m getting a B in my class and I am so upset about it. I know a B is still an okay grade but considering the fact that I get straight A’s it’s like a punch in the gut. Ughhh rant over. Does anyone have anything positive to say to cheer me up? I will really appreciate it. 😔