Thanks both of you for the good advices. After just 2 days I'm back to my "normal" FD status and nothing wrong wit the left hand. Seems like I needed some rest. However I discovered I was doing some things wrong; overpracticing, not enough sleep (stiff muscles when waking up is a potential invitation for Fd symptoms) and most of all going in too much mentally and psychologically.
Finding the right proportion of pracicing/relaxing is vital in my case. The hard part is when I miss a few days deliberately my hand and mind has enough time to relax but after returning my fingers get stiff even after cca 5 minutes. Then I start working again and a few days later Fd may spread in my whole body so I need to relax and I'm back to square one. A vicious circle it seems though I definitely progress very slowly.
