Consult with a local San Bernardino criminal attorney - some do not charge for an initial consultation. These charges are serious & you will need professional legal assistance. If you can afford an attorney & you qualify request the public defender. Your medical history may be of assistance depending on the facts of the incidents & review of your past & current medical records, etc.
This is not intended to be legal advise or as legal representation. I am a California personal injury attorney . Be aware that every state has its own statute of limitations; and statutes & case laws that govern the handling of these matters.
You are definitely going to need an attorney because a conviction for indecent exposure would require you to register as a sex offender. Since you are on SSI disability, I suspect you have no money for a private attorney. Have the court appoint a public defender for you and discuss the your case with them. And do not post any details on this site, as this is a public forum.
I can't tell from the question if your summary probation is in San Bernardino County or elsewhere, and that makes a big difference. If it is out of the court you are appearing in, sometimes the SB judges will try to screw you into a guilty plea on the new case by putting you in custody on the probation case. If the probation is elsewhere, they might just note it but deal with the matter in the normal course of a misdemenor arraignment. There are too many ifs to answer competently. Many of us handle cases in that court and you should contact one of us - it is always ill-advised to go into any of those courts alone, especially if you are on probation. www.kennedyforlaw.com
Talk to your attorney from your probation case. Many attorneys will deal with your probation violations as a part of their original fee agreement.
As for the new cases, sit down and talk with an attorney if you intend to seek private representation. Indecent exposure carries the penalty of lifetime registration, so it should be a major concern for you. You should begin to marshal your documentation regarding your disability and any psychological issues that may have led you to pull out your penis in a WalMart. If you don't intend to hire private counsel, you will probably be appointed a public defender when you go to court. Bring your documentation as well as a coherent summary of the case (from your perspective) and any defenses that you envision pursuing.
In the meantime, stop doing drugs and alcohol. Don't compound your problems with more inappropriate and illegal conduct.
You might also want to bring in information about what you intend to do once you're off disability, as the DA may be sympathetic if you can show that you are working to get off of public money, but a conviction here might derail your attempts to become a productive citizen.
Any statements I make in these forums (fora?) should not be taken as direct legal advice, merely informed guidance. This is true due to the anonymous nature of this venue, and the incomplete information which is invariably provided by the questions. It is imperative that you consult directly with an attorney regarding your specific situation before acting on or relying on anything represented here. Period.