I would suggest this, then:
Absolutely don't try feeding every 2-3 days. That only increases potential stress issues.
Move to a seven day feeding cycle. Try something small, that you can leave alone with the snake overnight. (Rat pup or f/t)
If the snake still doesn't eat, try again in seven days.
If they get overfed, they will start fasting at random intervals for varying amounts of time. I'm not saying you overfed...just that on an every five-day schedule, the snake may have gotten to the point where it felt like it had simply eaten enough for awhile.
At 200 grams (if that is a healthy body weight for his length), I would continue this routine for a good month or so before trying to switch things up yet again. Every time you try something new, you may be resetting the "settling in" clock. Some ball pythons don't take well to changes of any sort.