When comparing your mix to a commercially released song, bring the "professionally mixed/mastered song" into the project you're working in.
Use your ears to bring its fader down (probably quite a bit) until the apparent volume matches the volume of your mix.
Use Solo on the channel strip of the pro song to A-B back and forth until the volumes match.
Now, you can compare the things that you CAN compare.
Balance, Stereo Spread, Frequency Spectrum, Effects, etc
I'm back!