How can I protect myself while I am in the University and the only girl in my section from having a relationship even a pure one and I still have 2 years before finishing?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

At first, check Fatawa: 82431 and 83135 for Shari'a ruling concerning study at co-ed university.
In brief, it is not permitted to study at a co-ed University unless there is dire need. So, if you are forced to study at such a university, you have to avoid mixing and talking with men except when and where there is need.
As for your question 'how to protect myself from having a relationship even a pure one, we state that there is no the so-called "pure relation" except marriage. So, it is Haram to have such relationships between males and females as long as they are not married.
In addition, you have to remember that such relations bring down Allah's Wrath and that He The All-Knower of everything and He will hold you responsible for your actions.
Then, we advise you to befriend the righteous females and to isolate yourself from those female who are bad.
After that, you have to resort to Allah and pray to Him to save you from misdeeds, distress and temptation. At last, know that the best and optimum solution is to give up studying at a co-ed University and to join another educational institute that does not adopt policy of co-education, if it is possible.
Allah knows best.