Remove the steel strings immediately. They will permanently damage your guitar.
Do not use light-gauge steel strings either. You should only use nylon strings on this guitar.
Steel strings put much more tension on the neck of a guitar compared to nylon strings.
Guitars designed for steel strings have very stiff, strong necks with a metal truss rod inside the neck designed to counteract the additional tension from the steel strings.
Classical guitars designed for nylon strings generally do not have a truss rod in the neck, and the neck is built only to withstand the lower tension of the nylon strings.
Furthermore, the top of the classical guitar and the bridge are braced underneath only to withstand the much lower tension of the nylon strings.
If you keep those steel strings on your guitar, the neck will permanently bend and warp, the top of the guitar will "belly up" and warp, and the bridge will eventually rip loose from where it is glued to the top of the guitar, taking a good deal of the wood of the top of the guitar with it. When these things happen, then your guitar will be ruined. It will not be feasible to repair the damage.
Never, never put steel strings on a classical guitar built for nylon strings.
I did the maths based on data from string sets at the D'Addario string company web site.
A typical set of regular-gauge steel acoustic guitar strings puts 179 lbs (81.3kg) of tension on a guitar.
A typical set of nylon strings puts 83.6 lbs (37.9kg) of tension on a guitar.
Therefore if you put steel strings on a classical guitar, you are more than doubling the amount of tension and strain that the classical guitar has been built to handle.