And I was thinking that you might try taking those tough courses like Chemistry in another setting. My daughter graduated from college last year. She used her summers to take some of the courses she knew might be harder for her. She lived at home and worked during the summer, and took the classes online through a local community college and was able to get credit at her university for those classes. That way, she only had to focus on the one class and tended to do much better. I think I would also try a paid tutor to get you through the remainder of this semester. If you could get those classes behind you, perhaps you could proceed in your major and later enter graduate school. I know that I had to change my major in college because of the Chemistry class. I learned quickly that it wasn't my best subject so I switched to something else. I don't do what I studied in college for a living, but having that diploma has been helpful.
Good luck to you.