I'm surprised nobody has mentioned it already, but, in California, find your county's health center (usually a hospital, often more than one facility).

Contact them, possibly by just going to their primary care (ideally walk-in) clinic, and asking for advice or just to be seen by a physician. Even their full price for services, for uninsured low-income individuals, will be low, and, because that's often their target demographic, they'll tend to have a high concencentration of experts familiar with things like Medi-Cal.