That's an awful lot of different foods in a short space of time!!
The worming treatment may well upset his tum and affect his appetite for a bit, but beyond this, I think you need to choose a food and stick to it... puppy tummies can be very easily upset by abrupt changes in food, and changing too often can often lead to fussy eater, as the pup learns they can hold out for only the yummiest treats.
I'd stick with chicken and rice till his tummy settles and the worms are fully dealt with, then choose a decent kibble and put this down. You can soften it with some warm water (especially as he may well be teething at the minute and this can make crunching kibble more uncomfortable!). Leave it down for 15 minutes, then pick it up and give nothing else until his next meal.
I'm assuming he is on 4 meals a day at the minute? If he is already down to 3 (we changed at about this age) you can offer 4 times a day, until he starts eating, just so you can be sure he is getting enough opportunities to choose to eat...
If he doesn't eat anything for a whole day (as he's been poorly already), I'd be tempted to add a small amount of chicken to the soaked kibble, but mixed in really well, to see if this tempts him to start eating... but wean him off this as soon as he is eating.
Dogs won't starve themselves, so as long as he is drinking well and isn't otherwise unwell, I would play the mean Mum and if it isn't eaten, tough luck... though obviously as your pup has been unwell, as I say, you need to make sure he is over that first.