This is a confusion. One's own decisions are part of the physics that relate the present to the future. Basically you're doing a half-correction here; you're taking the naive view that one's decisions are something separate and outside determinism, and then noting, aha, but there is nothing separate and outside determinism, and then concluding that therefore there are no decisions; rather than properly adjusting the notion of decision to a deterministic world. Because decisions definitely happen! It's just that the idea of them as something separate and outside of physics was a bad description, not something that valid inferences can be drawn from.

Or maybe I should just link Eliezer Yudkowsky, because I primarily just don't really want to go down this rabbit-hole: https://www.lesswrong.com/posts/NEeW7eSXThPz7o4Ne/thou-art-p...