Good at Cash games but suck at tournaments!

i have heard many players say that they crush tourneys but suck at cash games.
while mine case is vice versa.
i am a cash player and have played a lot at 1/2$ and i have been taking shots at 10$ and 20$ tourneys!
generaaly the blind levels are like 5 to 6 min.
and you have a 100-120BB starting stack!
i see players going all in and making a lot of fool plays early on and i generally being card dead a lot of time play tight early on and suddenly i am like 20BB stack!
and then after that i have like fold shove stack!
what should i do?

Because of the rising cost of the blind, your stack falls. Tournaments differ in this factor from cash tables. You must consider this. The plus style of playing for cash tables does not always work in tournaments.

In the strategy section you will find a lot of good materials about the features of the game in tournament poker - try to learn them.

than play only cash and win money cash game its yours

I think a big learning point in multi table tourneys is knowing how your game called change early tourney mid tourney and late tourney. Just like hang so values change based on the number of players dealt into a hand.

In tournaments, the factor of luck is much more influenced, the dispersion is very high. We need a very long game distance to draw some conclusions about our game.

Stick to cash if you're printing money. If you play tourneys try to stick with the deeper stacked ones with structures that allow for more play

The 5-6 minute blinds you mentioned are an accelerated structure. You should play games with 10-20 minute blinds. The longer the levels, the more play you get for your chips. 5-6 minute blinds are going to force the action quickly. The shorter the levels are, the more of a gambling crapshoot a tournament becomes. Good luck!

I am tournament person and I suck at cash games lol.