I can focus on a red triangle for as long as I would like. I can also change any of my major habits that I would like (and I have done so recently).

I don't think that study shows that we don't control our own actions. Certainly 99%+ of our actions on a daily basis are instinctual/unconscious, but my unconscious is something that I consciously shape and develop over time. Nobody has perfect agency in a particular moment; your immediate choices are the outcome of the agency you exercised over the past months and years. You still have the free will to change, it just takes time.