Stop working if you can. If you only working for the extra money
and not to support your school fees, I suggest you stop before you
get burn out.
I was like you, working nights on weekdays and also working on
weekends sometimes up to 15-16 hours without much rest, end up
drinking about 3 cups of coffee to keep me awake everyday. Work
took up more time than my studies. Although I don't skip class, I
end up sleeping through them.
I was working for my school fees and pocket money, so no choice
lah. But going final year liao, my parents also want me to
concentrate on my final year project and also I see that should
have enough to support myself through the last year and so I
quitted my job.
Now, I got more spare time to do my own things(go out with friends,
etc) and concentrate on my studies.
It's really not worth it to let work drag down your school
performance, what for work so hard and earn so little and yet have
to sacrifice your studies? For me, I feel that it is better to
faster get my diploma and work in what I like (if possible) rather
than work like a bull and earn not even $600 per month.