You need to take this very seriously. Further, although I understand that you cannot afford a lawyer, you need a lawyer one way or the other.There is a good chance that you will face sanctions of some kind for having failed to promptly update your U4 form to disclose both your new firm and the misdemeanor charge pending against you. A great deal may depend on the nature of the misdemeanor charges, and your success in defending against them. The quicker you take steps to voluntarily remedy the situation the better off you will be. Presumably someone is representing you in defending the misdemeanor charges. If are truly cannot afford counsel, presumably there is a public defender who is helping you defend the criminal charges. Either way, you should discuss the FINRA problem with your lawyer and coordinate your defense of the misdemeanor charges with the FINRA licensing and reporting requirements.
One way or the other, you should not do this on your own--depending on the nature of the misdemeanor charges against you, this could cause career-threatening harm to you if not handled right. Thus, it possible you need to raise funds to pay for legal counsel---whether from family or friends. There are no short-cuts here. I wish I could make it easier for you, but the reality is that you need a lawyer---and lawyers ordinarily will not handle a matter like this without getting paid.