I sometimes have trouble controlling my laughter. Sometimes it happens in awkward or inopportune times. Do you know a way of how to control myself?
"For we all stumble in many ways. If anyone does not stumble in what he says, he is a perfect man, able to bridle the whole body as well" (James 3:2).
In your teenage years, self-control becomes a bigger issue. When you were young, people overlooked any lack of self-control on your part; instead, they looked to your parents to reign in your impulses. But it can't be that way all your life. Eventually you have to become responsible for your own actions. One of the things God teaches us is self-control (Galatians 5:22-23).
You are correct that there are times when laughter is not the appropriate response. There is "a time to weep and a time to laugh; a time to mourn and a time to dance" (Ecclesiastes 3:4). Sometimes when someone else is in a bad mood, being cheerful can be irritating. "Like one who takes off a garment on a cold day, or like vinegar on soda, is he who sings songs to a troubled heart" (Proverbs 25:20). The problem is that you aren't being sympathetic to what that person is feeling. "Rejoice with those who rejoice, and weep with those who weep" (Romans 12:15).
Now sometimes a person has a habit of covering up his embarrassment or nervousness with laughter. However, it almost always ends up being the wrong response for the situation. That is because he is focused on his own feelings instead of thinking about what other people need.
What you have to realize is that everything you think of doesn't need to be expressed. "He who restrains his words has knowledge, and he who has a cool spirit is a man of understanding. Even a fool, when he keeps silent, is considered wise; when he closes his lips, he is considered prudent" (Proverbs 17:27-28).
Ultimately, self-control has to come from you. It is self control. Others, like your parents, can point out that certain reactions are not appropriate, but you have to choose to learn and restrain yourself.