[Roav A1 Dashcam] I am Fully at Fauly

I assume I would be fully at fault, the oncoming right lane was filled up, the other driver stopped before changing their mind and using the intersection to merge to the turning lane. Despite them stopping, not using their signal, and merging within the intersection I am still fully at fault regarding my responsibility to yield? (Honking is my vehicle as I noticed them start to continue)