IMHO your chameleon should be in a cage at least the size of a 10 gallon tank at this age. By the time he is an adult the cage should be at least 2' x 18"x 2'high....and bigger is better.
I've never used rope but I imagine it would be okay if it wasn't that rough kind that could damage your chameleon's feet and of an appropriate size for him to grip. IMHO, it should be cleaned or replaced fairly often so that it doesn't carry bacteria.
You said, "I have been feeding him small well-feed crickets"...gutloading the insects is important not only to keep the insects healthy but some of what the insects eat will end up in the chameleon so its a way to get the nutrients that the chameleon needs into it. There is a gutload on ADCHAM that is recommended by many people....
http://adcham.com/html/husbandry/gutload.html
Supplementing/dusting (lightly) the insects when they are being fed to your chameleon is also important. If your chameleon is outside a lot so he can get direct sun then its always recommended that you DON'T give him extra vitamin D3, but insects still have a poor calcium to phosphorous ratio and he still needs some calcium. He also needs vitamins about twice a month. Caution needs to be used with vitamin D3 and vitamin A since they can be stored in the body and if too much is given, overdoses can result.
You said..."I tried to give it a wax worm today, but he didn't eat it he seemed to be afraid of it"...I have found that the first time waxworms are given to some baby chameleons they react that way. (Wax worms are quite fatty and are not a good thing to feed to your chameleon too often...they should be like a treat.)
You said..."I am afraid it is not getting the nutrition it needs" if you provide direct sunlight or full spectrum light including UVB (not through glass or plastic...and within 10-12" of where the chameleon sits) if he is housed indoors and keep him well hydrated, at a proper temperature (needed for digestion) and well fed with gutloaded/supplemented insects then his nutrition levels should be good. Use as wide a variety of insects as you can too.
Good luck with him! Chameleons are one of the harder lizards to keep well in captivity, but they are one of the most interesting too!