chill, dude! I had the exact same problem. I was used to mixing at very low levels cause of my mom, and when I first had a club system around me I was like "Hey! Turn it DOWN, I can't hear my next record" and fucked up all the time. But you get used to this. An important thing is a good CLOSED headphone that blocks a lot of the sound from the system.
You could practice this at home if you are in a basement or don't give a f**k about neighbors/parents. But I'd only do it for an hour a week or so cause it's pretty rough on your ears.

___________________

RetroActive 4

Where were you in relation to the speakers? Were you using monitor speakers? I would guess that you had the main speakers in front of you, facing away from you, and you did not have monitors. Am I right? This will make the sound that reaches you muffled and make it much harder to distinguish the beats. To counteract this, get a pair of monitor speakers and have them right next to you while you DJ, facing you.

Of course, I could be totally wrong, but hey.

the fact that you had it in your shed gave it away. the accoustics wouldnt have been the greatest

it was likely that the sound was echoing around and coming back to you at a later time to when it came out of the speaker. its called reverb, and if you had it what seemed as loud as a club then im assuming you were using subs, which would have made it impossible to mix accurately due to the constant whirring. i never really had this problem at parties like this because my mixer allowed for mulitple channel monitoring - i could just put on the headphones and block outside sounds.

you wont get this in clubs, they have engineers working there to make sure the sound is crisp and clear at all times and the dj is generally out of the speakers' 'reach'. allowing you to listen to whatever is coming through the feedback speakers next to you. this is not only good for accurate mixing, but helps prolong the somewhat short lifespan of your hearing

do you have an EQ on your mixer or amp? if yes, good.
in places with crappy acoustics, like garages, you will have to play with the EQ a little to make the sound be a little more clear.....
if you don't have an EQ on your mixer, or you tried playing with it and it doesn't work, GET MONITORS!!! and anyway, get good, closed, and loud headphones, so you can hear the next record better.
it should work.

___________________