Yup.
Until you can get some proper, relatively
flat speakers and maybe tinker your room to minimize problems, try comparing your mixes to commercial mixes you know sound good, A/B'ing back and forth. You may also want to try to use EQ on your stereo to get the most neutral response you can. Basically take four or five good sounding CDs and look for a
single EQ adjustment on your stereo that sounds good on all of them and then
leave it. (In fact, make a note of the settings so you can go back. You can always change them, but you don't want to change them around all the time or you'll never know
where you are.)
Anyhow, take heart, even my clumsy re-EQ seems to reveal to me that your mix is actually not too bad at all! Not to bad for flying almost blind, monitoring wise.
(But my re-EQ is certainly too jacked at the very high end -- gettin' some real fatigue listening to it... that's how us old cats know there's too much high end... we can't hear it but after a while it makes us edgy and cranky. Well...
something does. )