why am i not confident when speaking in hroup of 3 or 4 or more

Could be a lot of reasons. I was very shy at your age and my first presentation at work terrified me. But what I found over these years is to walk through fears like that which I had. Once on the other side it got easier. Then easier after that. I’m sure your opinion or input is no less of value than the others in your group.

A lot of people have social anxiety in some form or another, especially if you aren't familiar with the group you find yourself with. I imagine that it's different if you're with a group of friends, or at least people you know well? Or do you have difficulty in that case, as well?

It takes experience in getting up to speak and also confidence that you know what you are talking about. If you keep doing it, you'll grow into it and it will be ok. Don't worry about being nervous before time, that's natural.

For some people, two is company, three is a crowd.

Plus when it is a group, some people are simply left out of the conversation.

For those of us who are usually left out, we just do not like group chats.

Here's a trick just imagine them all naked and it's much easier but don't take the opportunity to start masturbating as they'll never forgive you for it.

sorry for your stress. Maybe in a bigger group maybe pick 1 and focus only on that person / see where that idea puts you ?

What’s a hroup ?

It takes practice. After a while it goes away and you develop a flow.

A meeting with more than 4 people is just a waste of time anyway

Anti-Social personality or simple social anxiety.

Just takes time and you will get there.

People are scary
With their thoughts

Past trauma comes to mind.

Focus on couple of friendly faces

Maybe you're a bit shy like me

Cause you're not? It's fine tbfh

Same