After installing GTM on Zaraz my website is getting no data. Why is this happening?

I copied my GTM code into Zaraz using the ‘Custom HTML’ tool; disabled the GTM plugin on my Wordpress site but since then the website stopped receiving data.

Is it possible to make GTM work within Zaraz?
Or I should recreate every event from scratch like I did inside GTM?

You probably want to recreate all the events you have in GTM inside Zaraz. Loading GTM as Custom HTML inside Zaraz will probably not give you any performance or security benefits.