hi duff,
your back acne is normal.
Back acne is however more difficult to treat compared to facial acne due the natur of tissues at the back.
another being that, the back is difficult to reach when applying acne creams and gels.
one important tip you should try out is to discontinue the use of back packs. as a student, back packs is a fad.
they actually worsen your back acne. so, stop it.
try out other simple natural acne tips like the use of fruits and vegs. yes they work. they work for me
More tips here:
Acne Treatment Tips