Stress is not additive. Stress is a multiplier.
Additive phenomena don't affect each other when they happen simultaneously. Multiplicative phenomena do.
You could have a health problem. You could have an argument with a co-worker. When one of these happen, your body goes through a certain amount of stress. But having an argument with a co-worker when you are not well is not the same. It makes you say things you wouldn't have otherwise said.
You may be able to handle a job loss, a recession, breakup or loss of a loved one if you face them one at a time. But if they all come to you at the same time you'll be hit pretty bad.
That is also why recessions are bad. It affects you from multiple directions all at once. Your job will be at stake, your home gets devalued, your work environment will pressure you to work harder, your customers will leave you and all of this will happen to your wife and friends at the same time.
When you commit to something, you are taking on stress. Don't do too many things at once.
Be careful with your investments
Investments by nature come with risk. you need to assess the amount of risk you already carry. Mortgage, job security, stocks etc all have a risk component.
Switching jobs, starting businesses all have risks. To take on new risk, you should not be highly leveraged. Listen to your gut, not the motivational speaker on youtube.
Be the diffuser
If you know everyone around you is in a stress time bomb, you can act to be the stress diffuser. You'll develop good relationships just as much in stressful times as in times of prosperity.