Popper is exactly right, btdt. If the GJ returns no true bill, you're free and under Texas law no one can sue you for anything afterward. Problem is the GJ does whatever the DA directs them to do so there might as well not even be one. You probably won't ever get your weapon back, and if you retained council immediately, you're out that money, typically $10-20,000. If they return a true bill, you get to lawyer up for realsies and fight it in court and/or work a plea deal. The wheels of the criminal injustice system are greased with plea deals and most courtroom politics plays out on the golf course, it is a hideous mess that makes government politics look like a child's tea party. Insurance would be a good idea but a better one would be start a defense fund savings account, that way the insurance company can't find some way to screw you out of your premiums on some obscure technicality.
In CA I have no advise, maybe easier to just let the thugs have their way with you.