Don’t worry too much about it, I was a very fussy eater as a child, parents tried force feeding, starvation and pretty much everything else. All these techniques achieved was to strain my relationship with my parents and damage my self-esteem. I was lucky that I got over it very young and now eat pretty much everything.
I have worked with very damaged and traumatised children for years, the most important skill in my line of work is patience. Weird quirks or “difficult” behaviour can be a symptom of another problem. Maybe your son does have ADHD, maybe he doesn’t (most diagnoses of ADHD in my experience do more harm than good) but I wouldn’t worry too much about all of this. I think the key to overcoming this is (and this sounds a lot easier than it is) to be patient, understanding, loving and accepting. Eventually, your son will become confident enough to try other foods and move on from whatever is causing him to get stuck with this issue. Oh, and get him to bed earler, 7pm is about right I think.
Give this website a good going over, it is right and (trust me) really does work…
Secure Base
At his age, it is more important that your son feels love and can trust you than it is for him to conform to “normal” patterns of behaviour imposed on him by people he grows to fear and mistrust.