HS Junior Year Struggle

Hi, this year Junior year classes have kicked my butt. I feel so defeated and plan on switching out of AP Chemistry. How bad will these C’s gonna hurt me for next year college apps? I also doing rowing and a lot of extracurriculars but Junior year hit me hard. I plan on dropping AP Chem and doing another science or another weighted class. Also does anyone have any advice they can give? My dream school is UCSD. I have strong extracurricular such as volunteering at a student leadership conference every year, student government, national honor society, rowing, and more community service.
Frosh
Semester 1
Biology - A
Integrated Math1 - A
English 1 - A
Spanish 1 - A
Student Gov - B (not calculated but just wanted to include student gov in there)
Semester 2
Biology- A
Math- A
HONORS English 1- A (switched to Honors)
Spanish 1- A
Student Gov - A
Unweighted GPA: 4.0 without Student Gov
Weighted GPA: 4.1

Sophomore Year
Sem 1
World History- A
Accelerated Integrated Math 2- B-
Spanish 2 - A
Honors English 2 -A
Honors Chemistry- A
Student Gov - A
Sem 2
WH - A
AIM2- C
Spanish 2- a
Honors English 2- A
Honors Chem - A
Student Gov - A
UW GPA: 3.85
Weighted 4.0

Junior Year
Accelerated Math 3- C-
US History - A
AP Chem- C
AP Lang- A
Spanish 3- A
UW GPA: 3.525
Weighted: 3.8 UC GPA.

I don’t have any advice about chem, but it looks like your math grades have taken a hit starting sophomore year. I highly suggest seeking out a tutor or forming a study group with other students. Don’t wait till the last week to talk to the teacher; go see your teacher before school, at break, lunch, or after school.

Chem is a tough subject. For me is the opposite, and is my favorite subject. What kind of textbook do you use? I may be able to give you some resources that may help you. How are you studying for chemistry? Let me know and I will see what is going on and why you are having a bad grade.