How can i sing like this ?

I have the same problem.I don't think I can help you, but, maybe we could talk, and tell each other about our problems........wait......that didn't come out right, let's just talk about it, and maybe we'll feel better. I always feel better when I get it out. :.)

i have stage fright too but going to a drama club helps to get your courage up because あなた will be doing shows and performing infront of peopleyou will get used to it i am starting to get less scared now about 歌う infront of people another thing that works (if あなた don't want to do drama または have a club near you) is get a 歌う lesson teacher to help i hope あなた feel better about 歌う soon :)