I am often laughed at by others, what should I do?

First of all, height is largely determined by genes and is determined innately. There is no need to feel inferior or put pressure on yourself.

Through exercise and some diet the day after tomorrow, it will also improve. I usually exercise more.

Secondly, you can use some humorous words to change the topic:

For example: Have you ever heard that condensation is the essence?

Being 1.8 meters tall is just a compensation for your ugliness...

The more others laugh at you, the harder you have to work hard. If you can't compare to others in terms of height, let's focus on other aspects. Crush others, come on.