Reply to done with arrangment. not loud enough?

i've completed a song and i'm pretty happy with the arrangement. i followed some tips from tarekith regarding the mixdown and left some headroom (i also have a version of the same song with very little headroom and one with no headroom). when i export any of these versions they dont seem to compare to other songs in volume. how can i get these to be louder without making it sound crappy?

obviously, i don't want to master it myself but i'm a college student and kinda broke atm. just thought i'd mess around with it for a while until i can send it off (probably to tarekith lol) for a pro mixdown/master.