I understand this issue, because I tend to be somewhat of a workaholic type myself and I end up going back to work shortly after injuring myself, being sick, or having surgery. I know it's not a good thing, and I don't care if people admire me for it. It's a very real problem that society doesn't acknowledge as being negative, because companies obviously profit more from overworking their employees. So we're conditioned to think that work is our "purpose" when it's honestly not really us (the workers) who are benefitting from it. Not unless you have a super high-end job, anyway.
Any type of financial benefit is obviously an incentive for people to work, because most of us have to pay rent or a mortgage, buy groceries, pay off medical bills, and pay for gas or transportation. Medical care can also be expensive depending on what country you live in. My country does not do a good job of taking care of the working class and low-income people, or disabled people, which is why we have a significant homelessness problem (in addition to poor quality and expensive healthcare, especially mental health care, and low-income and minority populations are the most negatively affected.)
The reason I work so much is because I like my job (I'm self-employed), but I also tend to hyperfocus and fixate on tasks. So whatever job I may have, I'm going to hyperfocus on it and I'm going to make sure I perform well. I'm the same way with schoolwork. I was always one of those annoying students who was the first to pass in my exams.
I also hyperfocus/fixate on routines, household chores, computer work, art projects, etc. It's exhausting. Sometimes I forget to eat when I'm working on something.
I don't know if this is just an autism thing, or if maybe I have OCD or something as well. I have been told that adults with ADHD can also hyperfixate on things, ironically.
It is an addiction and it can have a very negative impact on your life. If your boss is telling you that you should take it easy, you probably should. If you are overworking yourself for a financial reason, you might want to see if you can get paid leave if you have a serious injury or illness that is impacting your ability to work. And if you were injured in the workplace, there are things you can do to get compensation.
Information about work injury compensation in the US:
Workers' Compensation