Large company that I worked for 7 years fired me wrongfully. Case never went to court, but I received letter of judgement saying that if I processed anything further, that I will be in contempt of court. Is that legal?

What were you processing that led to the letter you received? If this has not gone to court, how can you be held in contempt of court, if you pursue what you were doing? Why did you get fired? Are you fighting for unemployment compensation?

I was processing documentation of case. The large company has their attorneys connected to the judges I guess. I feel that I was ignored. I got fired because I complained of sex descrimination. I received all of my unemployment benefits. I was fired in 1995. I am on social security disability now because of severe depression. I wonder if there is a statute of limitation? I have been unable to deal with all of this properly because of my condition.

Frankly it looks like you have not been able to prove your case. Proving a sex discrimination case especially 12 years ago, is difficult. I think you need to re examine your life and let go.

There is a statue of limitation , not up exactly on it but yes after all these years it would be long past.

First stop would have been the EEOC for review.
But if the court would not accept paperwork, it means one of three things, you did not have an attorney and was filing incorrect paper work, or you case had no merit and was not viewed as valid by the court. Or the SOL was over. They year or even the year after was when this needed to be filed.