Mental health is different than stress.

Some amount of stress can be healthy, as you pointed out, but when you overwork yourself endlessly, it takes a serious toll on your mental health.

Lifting weights properly leads to healthy muscles and growth. Lifting weights endlessly without rest leads to muscle injury.

It’s important to know where your limits are, and not to over exert yourself, both physically and mentally.

If the activity you are forcing yourself to do is making you depressed so much that you find yourself escaping from reality (alcohol, drugs, eating too much, sleeping too much, etc), odds are high that you are pushing yourself too hard.

My job was extremely stressful and it took a serious toll on my body. Whenever I wasn’t working, I was trying to forget work so I wouldn’t be stressed. This lead to me gaining a lot of weight and getting drunk and high all the time when I wasn’t working. When I quit my job, I just naturally stopped all of those bad habits and ended up losing 15 pounds in just two months.