Cinny is in a moderate workout level at the very most. He just needs a basic feed. My mare is spooky and "hot" as well as a hard keeper. I have her on a half pound of trotter and half pound of fat and fiber twice a day with her sinuex at night. She is on a round bale through the day and gets a large flake of hay when she comes in at night. She stays a healthy weight and still has a brain. She is 20 years old and events.
A common thought is "oh my horse is ridden 5 days a week so that's a heavy work load so I need to give him this this this and this and a touch of that and a bit of this to reduce the effects of this" and that is what creates a horse that is hot, high strung, spooky and ulcers and many other issues.
Hope you can figure out what is going on with him. But yes, I bet if you cut his feed back to the basic needs things would go a lot easier.