I used to be very shy and lacked confidence. Shyness is a barrier you can force yourself to overcome. Confidence is a fake it until you make it emotion. Rejection is a reality for all kinds of personal reasons for the person giving it, and not all of them have anything to do with you. It usually takes a lot of no’s to find a yes. Look at it like a game to a certain extent so the rejection doesn’t hit as hard when it happens, but be genuine and treat the people you’re interested in like people.