It says that my organization has exceeded the maximum limit for this feature. I found out that limit for such flow should be 2000, but error appears at 339 iteration. Can somebody explain why and how can i bypass this limit in such task?
For a flow, you can execute at most 2000 elements; in practice even a very small loop would be limited to about 500 records. Every box you see in your flow is an element, and every time you hit a new element, the flow's limit counter increments. You'll need to break up the Flow with some Pause elements to make it go asynchronous, or you'll want to just consider Apex, which can easily handle many times more records than a Flow can.