I have a gen2 Camry with 250,000 miles on the odometer and I had the same problems a couple of years ago. I had to use a hammer or wrench to tap the starter so it could spin and start up the car. I finally got sick of it and took it to a mechanic to install a remanufactured starter. My car haven't had a problem since. Since you've already been through 3 starter, i'm not sure what else to suggest. Maybe invest in a stronger battery with a high cold cranking amp rating so it can power the starter more. Or perhaps try to buy an OEM starter from toyota if they still make them. It'll probably be expensive, but it might be your last resort.