I am very sorry to learn of this situation.
Unfortunately the information that you received from the attorneys you have already contacted is correct. CA has a very aggressive statute of limitations for medical professionals/medical malpractice claims that bars claims that are brought more than one year after the plaintiff knows, or reasonably should have known, that a claim exists.
Keep in mind, the rule is that a "claim" exists - not necessarily knowing who exactly is responsible, or the extent of the injuries, this makes things much more challenging in a situation such as yours when you are acutely aware of the pressure sores on your legs for a period of greater than 3 years.
You can still report the facilities and professionals to their respective governing boards (there are a couple of different agencies that oversee hospitals in CA, so you will want to check the hospital that you were treated at and see who their governing agency is - it is almost always listed on their website). This can result in administrative action against the facility, but unfortunately it will not result in any compensation for you.
I do wish that I had a different answer for you as it appears that you have been very severely injured and disadvantaged economically by this matter, but the statute of limitations defense is very strong and the defendants would likely prevail in the very early stages (we call it the "pleading stage") of the action, which is why the attorneys you spoke to would not accept your case.
Again, I am very sorry.