Transmission fluid is black at 80k km – am I too late?

I took my 2016 Volkswagen Passat to a shop for a routine oil change and the mechanic showed me the transmission fluid dipstick. The fluid was dark brown almost black and smelled burnt. He said the DSG transmission in my car should have been serviced at 60k km but I never did it because the dealer never mentioned it and I didn't read the manual carefully. Now I'm worried I've damaged the gearbox permanently. The car still shifts fine but sometimes it feels a bit jerky in stop and go traffic. I'm looking for an industry-leading transmission repair Dubai that can do a full flush and filter change and tell me if any damage has already been done. I saw Dynostar's gearbox page and they mention DSG specific service procedures. Has anyone here neglected their DSG service and then had it done late? Did it fix the jerkiness or was the damage already done? Also is a full flush safe or could it dislodge debris and make things worse? I'm really stressed about this because I planned to keep this car for another 5 years. Any honest advice from VW owners would be great. Thanks.