Well, you could either get a new teacher, or perhaps simply fix your pronunciation! Just kidding. Maybe you just need to work on your confidence. Seriously, though, books have been written on the subject, but if you’re looking for more than general advice, if you want real help, you’re going to have to at a least upload some audio for us to hear your English. Vocaroo is very easy to use — you don’t need to sign up or anything. Just record or upload audio, copy the link, and paste it into an italki discussion.
For a few words of general advice, you can read the description for my course, “American Accent Mastery — Near native speaking and LISTENING skills — see description!” (You’ll find it on my teacher profile.)
Good luck, and feel free to inbox me when you've posted the audio, as I'd be happy to give it a listen.