The first thing to be seen is that it consists of several different ideas, and each idea would be better expressed if written in its own sentence. Let me show you and address the awkwardness of using the "out" prefix also. That should be eliminated for ease of construction and ease of communication.
Part #1: "He hid his pain by talking louder and longer than his classmates.
He continually tried to perform better than classmates.
His efforts at one-upmanship were obvious.
Part #2 The "apart from" is a bit of very confused writing.
The author is attempting a CONTRAST with another subject, but it is poorly conceived, and extremely "wordy". It does not make sense to begin with. So any misunderstanding is certainly not your fault.
" the occasional spiteful exchange with the more popular blue eyed Aryan jock loving girls"
This is intended, we may suppose, to be CONTRASTED with or COMPARED to another subject, but the other subject is not a subject that can be logically COMPARED to Part (a).
Part (b) managed to escape the worst effects on his self-confidence.
Here, you see the clause begin with a verb. COMPARISON with Part (a) would require a noun.
Part (a) and Part (b) need to be written as "stand alone" sentences, like this.
(a) He engaged in the occasional spiteful exchange
with the more popular blue eyed Aryan jock loving girls.
(b) Somehow, he managed to escape the worst effects on his self-confidence.
Composition is easier when the author writes in short, brief statements.