you just need more confidence because youre afraid of saying something stupid. whenever i need to act like i have confidence, i think of that episode of that 70's show where jackie is just acting chill and indifferent to everything. like when donna asks her if she wants to go to the mall, she's like, "thats cool." and donna's like, "well is that a yes or a no?" but anyways, so when i act like that, i dont have to talk until i feel comfortable talking, but i don't look shy.
i hope that helps at all.