This case became contested once you filed an answer. $900 is reasonable considering that the attorney may have normally charged $300 to $500 an hour. It adds up quickly. Most attorneys know that Landlord/Tenant awards are more modest, so consider this fee award low. Most court cases could cost tens of thousands of dollars.
You can appeal the decision, but that will cost a lot of money in attorney's fees.
I would contact the landlord or the attorney for the landlord, and see if you can come up with some sort of compromise. This may be accomplished if you move out voluntarily and pay or offer to pay any unpaid rent and some of the attorney's fees, but be ready to pay everything.
The best thing you can do is see if the other side will agree to some sort of settlement and agree to allow you to ask the court to vacate the judgement. Otherwise, make sure you get a full satisfaction of judgement, because this will go on your record for up to 10 years and will definitely affect your credit.
This is general legal advice intended for informational purposes only and does not create and attorney/client relationship. If you wish further advice, please contact an attorney of your own choosing or you may contact me for further advice and make other arrangements including retaining my services.
Since you lost by default, you evidently didn't respond to the complaint, and the case was tried without you there. You can check the court Web site for attorney fees allowed in uncontested matters. Without checking further, and without knowing the amount of the judgment, I would guess that $900 isn't too high.
You might find it most profitable to contact the attorney who won the case and try to negotiate a settlement amount that is less than the judgment, if you can. You might want to consult with an attorney for this.