I have a 98 Camry. Recently also went through similar trouble. The problem started from dripping oil under the oil pan. It was difficult to identify the cause. At first, I changed oil pan seal, but didn't solve the problem. Then, changing the crank shaft seal still didn't work. Finally, by running the engine with timing belt cover off, I saw the oil lead from the oil pump. Changing the oil pump O ring solved the problem.
Hopefully, you can find the problem.
Good luck.