Maybe its because your wrist is in a wrong position.
Originally Posted by piyushsood2312
When you go down on the fretboard(Low E to High e)
Your thumb should go from down to up.
Your wrist should be erect when playing on the lower strings and let it down when playing higher strings.\
Can't say it properly here. Try Lick Library's Speed Soloing By Andy James
It helped me gain some speed and became relaxed by playing fast too.
Green Skreamer Video Demo:-https://www.youtube.com/watch?v=F_nVh4C-Y-4
Guitars:- Cort KX5 Fr, Java EG-11, Givson G-215
Amplifier:- Laney LX12
Effects:- Boss Metal Zone, Digitech RP355, Zoom G1XN(for sale), Green Skreamer