Worried about 200 yd Fly.

It's my first time swimming it, and the most fly i've done is 100, and that was only twice. Any advice would be appreciated Oh, my shoulders have been bothering me at practice, mostly during free or backstroke. On the rotator cuff on my left arm, the top of the shoulders on both harms and on the sides. Would icing and heating be sufficient? or icy hot possibly? Thanks!