Damn if this ain't the hardest job ever...

This post is dedicated to all the poor teachers who have to deal with the youth of the world... I'd like to share with you the stuff that I have to deal with everyday, and I can assume that I am not the only one that deals with this crap.
First of all, each class has it's own individual personality.  I'm not sure if this applies to the US as much or not, I imagine that it does, however in Chile it is different because each class stays together for the ENTIRETY of their HS career.  ie these children rule their classroom.  So each class has it's own personality, atmosphere, for 4 years.... in addition, I split each class into half, so therefore I have actually twice the number of personalities to deal with.  In total, I have 22 personalities to deal with.  So if I were a superstar teacher.... I would taylor EACH class to their personality. But anyone who has ever taught will tell you that is just straight up impossible.  And I have it easier... typically the regular Chilean teachers have to teach the classes together, meaning sometimes times nearly 35-40 students at one time  (and we're talking all grades here, imagine 35 3rd graders, or 35 10th graders, or 35 7th graders... no matter the age, all is hell).  So I can handle 13 students, but the difference between 13 and 18 students is huge. 18 is nearly impossible to control so imagine 35... again.... THIRTY FIVE.  Furthermore I try to make my classes super interactive, fun, all while controlling the class AND having them actually speak, practice and learn English.  This is a huge task! I can honestly tell you that in my 9th and 10th grade classes I have had to pull apart boys from fighting (legit rage in their eyes and fear that they'd break a window in my room - which I have so far avoided and happens frequently to other windows). In fact, if i can say so myself, my room has remained fairly inhabitable.  All the other rooms, since the kids don't change classes, and I don't think rooms either for 4 years, they mark their territory with their names, scribble and whatever else you have and just completely destroy the school. Obviously this behavior is not ok in my classroom (and if Nicole would stop signing her name everywhere.... it would be better).  Anyways, the students here are crazy but their raised like that, and that's not to say they raise their kids wrong here, it's just they are raised in the society of mama's boys (and girls) - they are handed everything, and the revolves around them everywhere, except in my classroom.  and sometimes they are totally awesome and i can like TEACH! and other times i just have to create games to MANIPULATE them in behaving, shutting up, and speaking english. HOWEVER, this also often results in fights (whether fake or real) in 1o medio and 2o medio (9th and 10th grades).
I just dont understand sometimes how anyone learns anything for the following reasons: teachers regularly do not come to school for whatever reason (let's reflect on the society of mama's boys/girls. if you are slightly sick, under the weather, runny nose, you do not come to school for days.  imagine more serious sicknesses... we're talking kids and teachers out for weeks! it's bad enough having children miss school for weeks but imagine teachers missing school for weeks. that class, be it spanish language, or math, just goes untaught for WEEKS! there are no substitutes here.  depending on the time of the class, the students can just go home, and often don't return for their classes for the rest of the day, therefore there is no class of english for example.  i have a friend whose school is currently down one spanish language professor, one PE teacher, and i think science too.)
ok so imagine you have both teachers and students at school.  well guess what, there's an acto (like an assembly) or another teacher needs to class to take a test, or the students didn't finish their other work in their English class, or they skip, or they have to practice for a parade, or the English teacher has to give a speech at another school or.....  the reasons are endless. but I can say that this week I ONLY missed 2 classes... the week before it was 4 and again ONLY 2 the week before, bringing me to seeing each student 45 mins every TWO weeks.... and now you can see why my life is frustrating and really impossible.  I just hope I've maybe changed someone's impression of United States-ians or inspired someone to student more English in the future.
So with all this above, I am currently having trouble dealing with the fact it's impossible to actually 'make a difference' (what does that mean anyways), not feeling like a failure, and still being motivated (because I certainly cannot live and teach in a foreign country without a mission or motivation).  Advice anyone?? I mean it's a. not my place to change the system and b. impossible.  but do i just give in ...