Can I personally write the Judge a letter in my case asking him to look at the facts?

It's not appropriate to correspond directly with the judge without providing the other side the communication as well. A letter is also not the appropriate method to have the judge consider information in your case. There isn't much information in your inquiry.

You can't write to the judge. You can hire your own attorney to make your case to the court.

Ex parte[without notice] communication with the Judge is forbidden. Your letter will not reach the Judge, nor be read.

Neither you, nor your ex husband are allowed to communicate with the Judge without the other being there in person or sending them a copy of the Declaration that you are filing. It is improper to try to communicate personally with the Judge on your case. You should be explaining your side by filing a Request for Orders and Supporting Declaration of all relevant facts which support your request. Your other opportunity to share your side of the story is by your own testimony and that of your witnesses while at the court hearing. Keep in mind, that the information must be relevant to the issues that the Judge is determining on that day, not just a re-hashing of old information that he has heard before. It sounds as if you have a complicated case and need an attorney to help you prepare a good declaration so that the Judge fully understands your side of the story.

You need to rely on your attorney. If you don't have one, you should get one. The judge cannot consider a letter from you. That is an ex parte communication and he cannot look at it. The only thing the judge can look at are the pleadings in the file.

I really don't know if that will help since the Judges do look at the facts in cases. Normally all the pleadings are in the same file so Judge has access to everything when something is filed.

That would be inappropriate if you have been represented. If you have not you should engage an attorney and at least get counsel on how to approach the Court.