Chemical Reactions

If evolution is true then we are nothing but a series of chemical reactions. If this is true can we truly make our own decisions in other words control what chemical reactions take place. And if the part of us that controls what chemical reactions take place is in itself made up of a bunch of chemical reactions can we ever truly make our own decisions. And if we could, could we ever trust our own decision since we would have no control over them (being just chemical reactions). Or if we have a soul that is higher than our body (which is just chemical reactions), what chemical reaction made this soul form, and what are the chances of a series of chemical reactions creating a soul, or is it impossible for us to make our own decisions. And since you can't trust your own judgement because it might be based on a chemical imbalance how is there any chance of knowing what is right or wrong?p.s (chemical reaction)