i srugle sometimes when i read a easy sentence,but do better when i read in my head. what should i do?

You need both skills.

Try reading easy books out loud to young children. That will help you gain confidence and help you learn to pronounce the words.

But the most important reading skill is to understand what you read.

After you've read a paragraph to yourself (in your head), can you tell yourself the important information you've just read?