Since: Dec 04, 2007
First of all, what are your meters telling you?
By that, I mean, are you looking at a peak meter, peak RMS, or average RMS?
I think the situation is that your peaks may be hitting the same levels as other pieces of music, but your average RMS (the "meaty" part of the waveform) isn't getting enough volume.
So, while your peaks may be hitting -0.1dBfs, your average RMS may be more like -20dBfs.Commercial music is often anywhere between -16 RMS to -12, or even -10, which is f-ing loud! A good mix before mastering might have around -18dBfs to -16dBfs average RMS.
So, basically you need to figure out how to raise the "meat" of your music, but at the same time, you have to be careful that you don't decimate the peaks/transients too badly.
So yeah, trust what your ears are telling you. They are telling you it sounds too quiet. And it probably is!
That's basically how I interpret things, and I may be "not quite right" on certain details. This is kinda dipping a little into the area of mastering. Someone else with more knowledge could probably correct me at this point or offer a more detailed or refined explanation.