What is the reason for this big drop?

Hi mate,

Can you let me know the reason for this big drop in my website?

A update on big g in aprile, that if Google was the main traffic source

This could be due to updates causing the drop.

could be anything, really...

Better check your GSC for the pages and keywords that dropped, and then check which sites outranked you. Also check your backlinks, as many times (especially purchased) links can disappear, become nofollow, etc...

Last but not least, it could be a google update like everyone said. But probably the May update, not the April one, as your drop seems to have happened from May onwards...

Recently we faced spam backlinks and hacking on our websites. Is this the main reason we can see for this drop?