my first thread

i made a song today and i decided it was mean and ive put it on youtube. but i think it would be SO MUCH BETTER if it was mastered properly - ive noticed that when the mix has less going on at once some parts suddenly become extremely loud and painful then as soon as the bass is coming in you cant really hear it
i dont get long to play around with mastering because i am only using a fruityloops demo - and once ive got to the point of mastering ive probably spent about 5+ hours on the comp already - maybe when i get a new computer ill actually buy the software but i do not like the idea of downloading a pirated FL studio or reason or something, and it seems like having to start a new project everytime has helped me learn so much so fast
anyways can you guys give me some tips and some kind of general guideline for mastering? ive tried searching but nothing makes much sence.
http://www.youtube.com/watch?v=b0e5FeDCRPs
that video is what i made today, i used a multiband compressor on the master and on the sub bass but i dont even know if it did anything
if youl watch it youl hear the shrieking wobbly shit that hurts ur ears when the rest of the mix is quiet
would love it if someone can help me out CHEERS GUYS
