I know of several people who can put their hands up and say they ignored the light and the engines were lost because they were suffering from low oil pressure. Others will tell you that there are know reasons the light and alarm go off that are not a real issue with the engine.
First thing would be to make sure the engine is not suffering from low oil pressure. Do an oil/filter change and put in the best oil you can. If the problem still exists then then get a pressure test done, if the results are fine then I would change the sensors and check the wiring but the description you give is similar to mine and my engine started to seized in the end. My brother in laws went the same way.

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