Your insurance would also cover your car if your policy provides physical damage coverage of Collision. If you have Liability coverage only then there would be no coverage for any damage to your vehicle provided by your own insurance policy and you would have to go after your friend for the damages to your vehicle.
If your vehicle is totaled than if you have Collision coverage your insurance company should take the claim since you allowed the friend to drive your car. They would then pay you actual cash value for your vehicle. If you do not have this coverage than you would have to discuss with your friend how he is going to compensate you for totaling out your vehicle since his own insurance coverages (Collision or Liability) would not cover your vehicle in this situation. Insurance follows a car first and driver second so your insurance would need to be primary and cover your car if you have the right coverages.
If you get another car you can get a car insurance quote here.