Captive iguanas often have difficulty with the expression of their sexuality.
Find the mating season articles in here:
Breeding season is very complicated for captives.
Generally for captives it happens at any time, but mostly between November and April.
Yours never had the wilderness experience of the general iguana mating season. During that time, the males get pushed out of their territories by other igs who are trying to force more females into their harems. A young iguana would see that going on. He instinctively understands it. That would teach him about his "in season" behaviors for defense and gathering, if not for that year, then in the next few years.
Captive males are very erratic about their seasonal responses. Some turn orange and get very aggressive in their first season or at 1 1/2 years old. Others never have a 'season', and others have a season after living a long time. Some have light-duty seasons, others have heavy-duty ones. Some go into season and never come out, others' seasons last a couple of months. If he doesn't revert to tame in a year or two, you have to re-tame him (see below at bottom).
Caution: Never get into any kind of confrontation where he can end up feeling like he drove you away.
So, other things that cause aggression. If yours has discovered how to see his reflection in the glass of his habitat, that will stress him out a lot, triggering his territorial defense instinct. He would certainly go at least a bit nuts if that were happening. You can counter that by placing cardboard over the bottom six inches of any glazing he can get at. Whenever it is more bright outside his hab than inside, the glass or plexi-g will reflect like a mirror on the inside. Placing him in a portable cage and putting him in a dark closet for a week can break a season that is unnatural or unending. I've read that two weeks is often needed. It's not a sure thing.
Injuries, pain, and organic medical problems can make an ig very troublesome. It IS time to take him to a good exotics vet for a checkup. He should have x-rays, a blood lab, and a fecal exam.
You mention that you have moved. Did his troubles start after that event? Iguanas hate change. Read Anapsid's article "Ch-ch-ch-change!!" Some never pull out of change-related stress on their own. In that case he needs to be gently but carefully and very firmly re-tamed. But with an ig that large you have to be willing to fight hard and donate some skin to the cause. And you have to do it right or you could be seriously injured. However there is a definitive way to do that. I can give more advice about that. Feel free to ask.
Hope you see this and I hope it helps.