He needs more support from his family specially his father Kostya, I think they have reconciled years ago, and that's why Tim is really fighting very good until that Fundora fight. So maybe he needs to take a break and then go for a easy fight mid next year. Just took a break from boxing for him for now will be a good suggestion.
Tszyu took an unnecessary amount of damage in the Fundora fight. When a fighter is practically blind from all the blood pouring down their face, the referee or the corner should have been looking out for him and stopped it. His promoter also should have matched him with an easier opponent after that brutal fight. Now we are seeing the consequences of those decisions and Tim might not be the same again.
Yes, that damage though in the Fundora fight, one of the worst experience for a boxer. He might have the heart to survived that fight, but after, it was a totally different mindset for him as we can see his eyes during the first knock down.
Perhaps during his reign at 154 lbs, there are no solid names that time that's why he was able to get a title and fighting comfortably in Australia. Then he face Tony Harrison and knock him out making a statement and that time it was only Charlo who has the hold of the belt. But now, in just short amount of time, like 2-3 years, it was a different landscape at 154 lbs and it did show that he doesn't have what it takes to be the king of this division.