Back off a little on the level. If you have the option to remix, you might be able to get the loudness you're looking for there by adjusting individual levels instead of at the mastering stage with a compressor. After the acapella intro, I think the guitar needs a little more volume. You would probably have to back it off again when the rest of the instruments come in to retain the balance you already have there (which seems to be working well. Great voice BTW.
Here's 2 little tips that might help in general.
1. If you want to get a better idea of what a particular control (knob, slider, etc...) your turning does (like ratio or threshold), play your mix back at normal volume and turn that knob all the way one way and listen for a minute. Then turn the opposite way and listen again. Once your ears hear the large difference in sounds, you'll have a better idea what you are listening for. You can use this for just about any effect/control. Sometimes the change is so subtle that what your hearing and what you think your hearing doesn't coincide. You need to 'tune' your ears to the change your about to make.
2. Find a commercially recorded song that is similar to your song. Something that is of the same genre, tempo and style (as close as you can find). Even without using your ears at all, play the commercial recording on something that has a spectrum anylizer. You could use something like Wavelab if you have access to it (I was just using the cheesy one in winamp). what you are looking for is the overall level. Obviously, all of the bands in the spectrum are bouncing all over the place. You're just trying to find the average level. Now play your recording. If there is a big difference ('Be Somebody' was maxing out almost all of them almost all the time) between the two, adjust the levels, or back off on the compression to get them a little closer to what you saw on the commercial recording.
Because music is so subjective, and everyone has there individual tastes, this is only a very rough starting point. You'll of course tweak to suit your own tastes. The Spectrum anylizer trick takes your ears out of the equasion, and gets you in the ballpark of the commercial recording's signal levels. Bear in mind that the people engineering and mastering albums for major label(or even minor labels) usually have much experience behind them. You can use their recordings, mixes, and masters as a guidline for your own.