I thought it might make sense to look at your games to help answer your question, but I see a whole lot of time-outs. Any reason why?
Typically, the better you get at slow chess, the better your blitz rating gets as as your stored mental database of patterns (augmented by tons of slow + serious games) become a lethal arsenal under short time controls.
FIDE 2050 is a federation rating. I did not know FIDE had something called a blitz rating? Could you clarify? Or were you comparing a FIDE rating to an online blitz rating?
In the last 2 years I went from 1800 fide to 2050 but my Blitz rating went up only 100 points! I am playing few Blitz but that can`t be the reason!? Teahers say one can improve Blitz by training, but they also say anyone can become a 2400 fide player. I think these teachers don`t know what they are talking about? I see some kids with the same fide rating like me has 400 points more than I in Blitz. So good in Blitz means simply faster not better? Just like ability to play blindfold is just memory.(quoted Kasparov).