Congrats, you have a very good work ethic but a very poor personal health ethic.

I was like you, and probably still am deep below, and I will fall again in the same trap. But please, try to think about flipping your point of view here and instead of being your manager generous and your company good for not taking into account the time you failed to answer on duty, think about how you are being exploited covering 75% of on duty alone, and the money the company didn't loose just because of you. And how much of that money you got.