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

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.