OK this is the current state law concerning concealed carry at colleges & universities in Texas. I'm assuming you are asking about those places because you say you are a student and the carry age is 21 for Tx CHL so that rules out you being a high school student.
CHL holders must secure their handguns in their vehicles when on a campus. Tx CHL holders CANNOT carry on their person on a campus. PERIOD.
Your instructor was very wrong and should be told that. If he continues to argue that he is right, DPS needs to be told about him, and he needs his instructor's license pulled by DPS. If you violate the above it is a felony. The law before this did not allow CHL holders to store their weapons in their vehicles. The current law allows vehicle storage.
Non CHL holders cannot have handgun in a vehicle on a campus.
No one can have a rifle or shotgun in their vehicles (or on their person) on a campus.
The above is not a discussion of whether the Texas CHL laws are good or bad, just a description of what the laws really states. A person's feelings about a law is a moot point. Laws in Texas get changed every two years. While something is a law, it should be obeyed.
Look at page 50 of this http://www.txdps.state.tx.us/interne...rms/chl-16.pdf
. Securing the handgun in your vehicle does not violate the above (page 50) if bystanders do not observe the weapon during the process of it being secured.