How to be confident with my body and mind?

In recent years i have not felt like a confident person at all. I was once but i think i've forgotten how to be confident. I'm trying to change my mind set and put myself out there more, be more outgoing, but i feel like my body language won't follow what my mind wants. I think i always look insecure, it seems like i can't keep myself from fidgeting with my hands or clinging to my purse whenever i am walking or speaking with someone. I think i am pretty yet i can't exude an air of confidence or sexiness, like i don't know how to move my body, i feel like i move awkward or clumsily because i don't know how to just strut my stuff. What should i do? Do i work on my mind more to improve my body, or work my body by taking a dance class or something? I don't know which is causing the problems. Ideas?