hazel -
As long as you have an agreement in writing with your landlord that they will allow you to pay extra every month to catch up on the arrearage on your rent, I think you will be fine. If you don't have an agreement in writing on this, I would say get one as soon as possible to protect yourself.
I would not allow this to get behind if you can at all help it - rent/house payment always comes first - you need shelter - then utility bills, food, and car - then other debts. I don't think a judge would set payments for you - if it comes to the point where the landlord evicts you for non-payment, the judge is simply going to set up payments for the arrearages - you will still be evicted.