What steps do I need to take..?

I'll try to make this short.

About a year and a half ago I started receiving letters from a junk debt buyer requesting payments. I genuinely DO want to take care of my debts and I contacted him via email and agreed to pay back 3300. (I realize now in retrospect that I am a complete idiot.. my original credit limit was 2500/ of which I never exceeded 1200 when it went into collections). By a stroke of sheer luck, I contacted him to apologize that the first payment hadn't gone through (I set up Bill pay through a new bank account for documentation purposes and typed his address in incorrectly). Well it turns out he was taking me to court in like a day or two and I had no clue. He cancelled it, but about 3 months later I got an alert on my credit report and saw I had a judgement against me. I contacted his office and one of his minions said I now owed 4200 per a judgement against me... This man was in DIRECT CONTACT with me. Isn't he legally responsible for notifying me?? On top of this... his associate told me I now owed 4200 by judgement, but the court website says 3400. So do I owe him anything past that amount?

Again, I realize I am a complete idiot for evening paying a dime, but what's done is done. I'm wondering now if I have any options and what they are. What I would really like at this point in time is to get this judgment removed. I've done enough damage to my credit score, and this just dragged it down lower!

Any genuine advice is greatly appreciated!!