I have lost 10 rapid games in a row. What is wrong with me.

Just take a break for a few days and you will start to win again.

I have had streaks of 14 consecutive rated blitz losses, so this is nothing to worry about

Losing 10 games in a row, even though quite demoralizing when it happens, is not that uncommon. It happens to much stronger players too. And it'll most likely happen to you again even if you get much better, because your opposition will get better too.

Take a break if it tilts you. There's not much else you can do in the short run. Keep at it, continue improving, and in the future you will be losing to stronger players

The other day i reached my peak elo of about 800 then i lost hundreds of poinst for about a week

so yes i think its a phase. if you look at Levy Rozman or Hikaura Nakamura's stats then you can see dips of as much as 400 points more than once.