Rapid (10 minute) vs. Blitz (3 minute) - Large discrepency

I am so bad at blitz. My rapid elo is about 750-800. My Blitz elo is about 500 lower. I take that to mean a few things.

First, I don't know openings really. I play around with the london and caro kahn. That is it. I know about 3-5 moved into the opening at best. I need to try to be better at the opening, but memorizing openings is not my idea of fun. However, it is awful getting crushed out the opening.

Second, I have no "intuition" for chess. I need time to think to play even a little "well." A 700-800 does not really "calculate," but I am dependent on the little calculating that I do to have any chance of winning. Take that away, I have absolutely nothing.

Third, I get paralyzed by indecision when I can't calculate. I miss basic tactics and make huge blunders. Tunnel vision is very real. Heck, I have time trouble with a 10 minute rapid game. I started playing blitz to help work on my time control. It hasn't helped at all. The amount of games I lose in winning positions is way to much. A 3 minute blitz game is hell on earth for me. My brain doesn't think that fast. It is soul crushing. Playing more has not helped. I don't get mad if I lose a rapid game, even if I blunder. However, blitz makes me so angry, and I am not an angry person by nature. The amount of times I've acted in anger in blitz is about 100 to 1 compared to rapid. I even found myself being childish at times, and intentionally giving away pieces instead of resigning. It brings the absolute worse in me.

Blitz is soul crushing.

I think I need to try something else other than blitz to help me make quicker decisions in my rapid game. Any one have any advice? Anyone feel the same? I feel like the biggest idiot when I play blitz.