Recording level and volume are two different things. When you are recording, you need to fill up the input meters about half way. Spikes and transients can be above the half way point, but the bulk of the signal needs to sit there.
If you are having a hard time hearing the guitar over the rest of the music, turn the other stuff down. Unless you recorded it at the level I just described, you recorded it too hot. As you add tracks that are too hot, the mix will get out of contol volume-wise.
Recording level, monitoring level, and mix level are three different things that have nothing to do with each other.