Can't connect to my WinSCP

Hello, every time I try to connect my WinSCP it says Lost Connection. Sometimes it connects pretty well. Once I open any file it is empty, after couple of seconds a Lost Connection tab pops up. Then it reconnects itself and a fairy tale without end. I checked my internet speed couple of times, but it has the same speed as it was before when my WinSCP was working. Also I can not drag and drop my new files to WinSCP. If somebody could help me it would be very grateful.

What protocol are you using? Do you have better experience with any other client using the same protocol?