taking university courses as ESL

there's a huge population of ppl at my university who know english as a second (or third or fourth etc.) language and omg how do they do it. i only know english and it's difficult enough. HOW. can you absorb an entire course load of content founded on the basis of a foreign language and not only pass but EXCEL at it. they make it look easy. my brother has to make a group paper and his groupmate was editing his work and he was PISSED not because she was changing his work but because she was fucking owning him in terms of eloquence and tone. her first language is mandarin. HOW. lol i sound like greg heffley with the way i'm capitalizing things but i'm just so flabberghasted.  maybe i should get off the computer and get my head in the books! that reminds me my ex boyfriend was born and raised in Vietnam and when he spoke to me in english he was using words i had to look up the meaning of :,D literally. maybe english is a stupid language and compared to other languages it's easy to learn? i don't know. i've always been under the impression that english is quite frustrating to learn but i think that might just be because of its inconsistencies. i just find it so interesting because i would even consider myself to be quite an articulate person compared to most native english speakers, but these ESL people bro they're making english their BITCH. and they've only known the language for a couple years compared to my 20+ years. i need to up my game.