3.77 GPA is nothing to sneeze at.
It is great that you have motivation for human biology because it will matter later for more advanced courses, research, and your career after college.
I want to point out it’s impressive that even though you did poorly on the first midterm, you did better with the second midterm and the final as it’s more typical for students to go the opposite direction.
I think Chem 3A’s reputation is about as bad as Chem 1A. It’s not easy, but these are basic fundamental courses that have the examples and excellent explanations in the web as needed. Not ‘getting it’ won’t be an issue as long as you try.
Also, I think boyfriends are kinda overrated. Life is busy taking care of what’s important now.
I had some excellent luck visiting the Tang Center counseling during the times when the anxiety was more than I can handle. There were excellent professionals whom I talked about the rough moments which itself was reliving, but also hear back deep insights and eventually learn how to handle the rough moments.