Please do not say bad things. Help me with this situation. Homeowners has sent me a "default " letter.?

Now I am low income. I cannot pay more than 1/3 of the fee which i have been paying for many months. I use to be able to pay but my brother moved out (we are on peaceful terms). Now I thought they cannot take you to court if you paid something? Well, they cannot get blood out of a turnip. I called them. No return call. doented stuff, have all my partial payments. What can they do to me? This is really awful.( Are they just threatening me?)...because I had written them a nice diplomatic letter explaining my situation and what i am ABLE to pay. What happens next? Honest answers by anyone in the court house or an attorney.