Most people take Pre Calculus as their fourth math credit, but my teacher didn’t recommend me to take that next year because i got a C for Algebra II last semester, therefore PreCalculus would be though for me. And i can’t take PreCalculus next year without my teacher’s approval. Maybe if i talk to him, but i feel shy to do that especially because my grade is not in my favor.
Is it really that important to take PreCalculus? Would’t that look bad to colleges that i wasn’t good enough to take PreCalculus like most seniors? Isn’t that required if i wanna apply for some more selective colleges? Should i talk to my teacher? 
I suggest that you talk to your teacher and guidance counselor and follow their recommendation. As an aside, students applying to top colleges generally take calculus senior year. Keep in mind that there are tons of amazing colleges and universities out there so seek out ones that fit your academic and financial profile.
If your potential college majors require precalculus or calculus as a prerequisite to something, then stopping high school math at algebra 2 means that you will have to take precalculus as a remedial course in college.
Is there another math you can take senior year that would help prepare you for pre-calculus? You likely do need a more solid background than a C in Algebra II gives you if you are going forward in math. Could you retake Algebra II either at the HS or a local CC - just to gain the knowledge?
You can take Pre-Cal over the summer (do it somewhere outside your school so it doesn’t go on your transcript) and take it again in senior year so you don’t fail the course.