I know that you are worried and confused. Lots of people are "throwing" different things at you to try and help you figure out what to do. Usually the first thing you want to do is stabilize them so the probiotics and/or electrolytes are good common starts anytime a Chicken doesn't seem right. If there is a vet that you can call and at least talk to (I know that oftentimes vet schools will have someone you can talk to). They may can give you more information about what you can do to try and help if no vet is available. Also having a picture helps the experts here get a feel for what is going on. I suspect that you may not have posted enough to allow pictures (I don't remember how many posts you have to have but someone else may know). I think it is like 20 posts. For lack of a picture, try to describe what you see with as much detail as you can. IE you said his neck is "not right". Is his head always flopping to the same side, or turned a specific way (wry neck maybe), or does he have limited control. The purple wattle definitely sounds like there is some circulation problems. This could be something neurologic (dealing with messages to and from the brain), or something limiting oxygen getting into the blood.
You said that he is not eating/ drinking unless you force him to. I wonder if he has something caught in his crop. One person suggested feeling the crop area ( just down from the throat) does he have a bulge, or is it very thin. Feel the area and then describe what you feel. Besides not crowing, is he walking around, sleeping alot, alert, etc. What does his poop look like? watery, solid, normal, different color? All of these provide clues. Once we have a better idea, then we will be able to give you more specific information that is not just guessing.
Good luck and keep us posted.