If I was recently in an accident and now have back pain, what should O do if he other party’s insurance adjuster wants to come to my home to see me?

Depends on how serious your injury is. If you don't need anymore treatment then cooperate with the adjuster. If your injury is ongoing and you may need ongoing care for awhile, I would get an attorney before giving any statement to the carrier.

The insurance adjuster will want to take your recorded statement as to what occurred in the accident.  This is standard operating procedure.  Don't discuss anything about your medical condition. 

If you were not at fault in the accident and the other party's insurance company is accepting liability, you can get medical treatment from a doctor, who is willing to accept a lien.  This means the doctor is paid out of the settlement of the case.  When you complete your medical treatment and are released by the doctor or are declared by the doctor to be permanent and stationary which means having reached a point in your medical treatment where no further improvement is anticipated, obtain your medical bills, medical reports and documentation of any wage loss.  Your personal injury claim filed with the at-fault party's insurance carrier should include these items.  Compensation for the medical bills is straight reimbursement.  Compensation for wage loss is straight reimbursement.  The medical reports will document the nature and extent of your injury and will be used to determine compensation for pain and suffering, which is an amount in addition to the medical bills.  If the case is settled with the at-fault party's insurance carrier, NO lawsuit is filed.  If you are dissatisfied with settlement offers from the insurance carrier, reject the settlement offers and sue the at-fault party for negligence.  If the case is NOT settled with the insurance carrier, you will need to file your lawsuit for negligence against the at-fault party (registered owner of the vehicle if other than the at-fault driver) prior to the expiration of the applicable statute of limitations or you will lose your rights forever in the matter.  CA has  a two year statute of limitations in a personal injury case which means the lawsuit must be filed prior to the two year anniversary of the auto accident.

The property damage to your car is separate from the personal injury claim and is usually settled early in the case with the at-fault party's insurance carrier.