Definitely medium size bindings.
Also, a regular width board - but sounds like that ship has sailed...
This is simple. Your board is too wide and your bindings are too big.
A 26.8 waist needs at the very least a 12. You're a size and a half too small for that board in reality. And you have almost no toe overhang in that binding. Mediums are a better fit.
Thank you. That is is the basic problem and no messing around with the bindings is going to address this fundamental issue.