Bad grades in highschool?

Ok, well this is my second semester of 10th grade. I don't know why, I just never do anything for school these days.. I just cant concentrate! And so it obviously has affected my grades. In freshmen year I got:

Adv. Science- B B

Pre- AP English- A A

Spanish II A A

Adv. US Gov. and OK history A A

Algebra I A A

My high school has a block schedule so:

AP World History B B (5pts for A, 4 for B...)

Pre- AP English II A A

Geometry A B

Current grades in classes Im currently taking:

Spanish III C (D': This is my first C ever!!)

AP World History B (Just barely! its a 79.9)

Algebra II B (81)

Biology B (85)

I was always able to bring B’s up to A's before the semester ended!! Since we have a block schedule, grades get recorded per nine weeks in high school and this nine weeks is ending on like Mar. 15!!! Will it seriously damage my GPA? , if I'm able bring everything up to an A except AP World and Spanish? My parents are going to freak! My sister always did exceptional at school and they expect me to do just as well! Will it hurt my chances of going to college?

Also, do you think the classes I'm taking next year will help?

AP English III

American History (AP is offered but I dont think I could handle it)

Pre- Calc and Trig

Pre-AP Chemistry

Human Anatomy and Physiology

Zoology (if not this then genetics)

Business Management and Supervision

Meteorology

Astronomy

I THINK I want to do medicine, but I'm not quite sure, that's why I'm taking so many sciences... Another reason is that my school doesn't offer any other interesting classes :P