One of the important causes of stress is that we have high expectations. From everyone. We expect our jobs to be easy. We expect our colleagues to be nice. We expect the car to run smoothly everyday.

We even expect others to understand our feelings without telling them!
Likewise, we keep high expectations from ourselves. We expect to lose weight in 15 days, finish work before deadlines, get good sleep every night, have a good social life, be the best spouse/offspring/sibling/ employee/neighbour etc. etc.
And we want all of this as quickly as possible. We want it like ‘yesterday’.
How can one person have all of his/her expectations met?
It is not possible to get all this without affecting your health. You can try to improve yourself. But expecting the world to run as per your wishes, is impossible. Eventually, you will get frustrated. Frustration leads to stress.
So lower your expectations. From everyone including yourself. Lead a simple life. Aim to improve only yourself. One quality at a time. Do not hurry. Relax.