Turbo (P0299) and V-belt problems

Hello forum, I need help for my 2012 i30 FDH with 1.6 CRDi and 90PS. Yesterday I missed on the way to work performance and later on the highway the engine control light started to flash. The error was P0299 turbocharger underload. After the deletion the error unfortunately came back within 30km. Overall I had to drive almost 200km with the condition. Today I looked at the turbo times, but could not find anything obvious. VTG adjustment is already s The problem shouldn’t be over 50,000km long. But luckily I found out that only 50% of the width of the belt is left… Does anyone have any experience with the error and could the belt be a cause or a consequence? The belt can’t be broken for a long time, a few days ago I saw it completely when I switched the bulb to VR. At just under 240,000km the consideration is already whether I should put a lot into the box, last year the clutch was due. The turbo is not quite cheap and if other parts are affected, then it is probably rather an economic total damage. Although I want to give it extremely reluctantly, since so far really reliable. Do you have idea and suggestions? Thanks and greetings Sascha