First point to remember is ratings aren't an absolute measure like distance or weight. It's a statistical distribution that compares you to other players in the pool. Especially for U2000 the blitz pool on chess.com is tougher then the turn-based stuff.
Blitz is mostly played by experienced strong players for fun... they play their serious games at tournaments. So especially if you're newer to chess I can imagine your blitz rating will be quite low... there's no time to think and you don't have a lot of patterns in long term memory (essential for rapid play).
About everyone has a few hundred point gap between live and turn-based. 700 is a lot, but if you're new to blitz and especially new-ish to chess then this kind of gap is not unreasonable.
To improve, you can work your way into it. If you use the analysis board a lot then you're probably not used to calculating/visualizing. Start with "standard" time ( > 15 minutes) and work your way into blitz as you get familiar with openings and calculating.
I am going crazy with this game and I'm certainly not the only one. I'm currently playing playing turn based (3days), 30 min semi rapid and 10 minute blitzes. Although I take my turn based rating with a grain of salt, I am below 1000 in blitzes, hovering around the 1150 mark for 30 minutes and 1700 in turn base?! As soon as the clock goes I get so stressed I can't think. The slower the better I guess. Any advice to improve my nerves in faster paced games? Thanks in advance!