The way of my study  that I study

Yours: As a college student, I leaning spanish now,but I feel I will forget English,the grammers and words,even when I face foreign teacher who teaching English,I just only understand what they said,and I can't answer their qustion in English,the spanish words full with my head,I don't konw how to handing this question.

Rather than having all of your ideas in one sentence (this is a big run-on!), I would split the sentence up into a few sentences.

Mine: As a college student, I'm learning Spanish now but I worry that I will forget my English. Even when I face the teacher who teaches English, I only understand what he says, and can't answer his questions in English. My head is filled with Spanish words and phrases, and I don't know how to handle this problem. 

Hope this helped! Keep writing!