Please don't get excited yet. I have done so too, way too many times.
Give it six months. Yes. That long.
Three days, three weeks, and even three months means little with our kids. They do sometimes have good days, weeks, and Kay has had a very few good months. Up to almost three. Almost.
Since Kay won't cut out the unmotivating pot and refuses to get professional hielp for her psychiatric issues, she can not sustain. Plus pot may be okay for some, but it has a bad effect on Kay. Its not benign for everybody.
I can not speak about your son. I don't know him. All I know is that our Kay has disappointed us so many times that we no longer get excited about upturns because for her they don't last.
I hope for you it is different.
Be well.