Bike fit help needed

not a great picture, a video of you on the trainer would help show a lot more.

That said, you are sitting up quite high. (that is, not aerodynamic) saddle may also be low, but it's very hard to tell from that picture.

Have you had a bike fit? If no, it should be at the top of your list. If yes, you should go get a refund.

Could be a couple of things... In terms of fit, more then likely saddle position too high and/or too far back. Could also be pedaling technique or excessively high cadence (especially if you ride a really light gear which tends to make you bounce, you need some resistance).

The photo didn't load for me, so I can't comment on general fit.