seo: shutting down a website correctly and maintaining localized versions in different tld's

I have a website that is available in 6 countries. All versions operate under their own country. tld With different content and language (except the English version that uses .com). For example, the French version uses a .fr the domain and all the content is written in French and so on … (All websites have different content, not the same content in different languages).

So the situation is that I really ruined the .com Site with some redirects, changes to the URL structure and deletion / updates of content. Although it did not receive any penalty, the search traffic was reduced by 95% and it does not seem like it will return (I was waiting 2 months).

Honestly, I really do not mind fixing it because it was the least popular version and did not generate any income. So now, I'm thinking that closing the site would make my life easier. I'm a little afraid that the .com landed in the security room or simply violated a Google line after updating the design and content, which may affect the other versions in the other domains.

My question is: is there any recommended way to close a website without damaging the other domains? Like simply redirecting all subpages to the homepage, erasing everything and simply keeping the Error 500 pages
or using 410 headers

Or should I not be afraid at all because there is no possibility that Google punishes the other domains just because they are using the same domain and managed under the same GWT / Analytics account?

It is important that the other websites did not get the redirects and modifications that caused the problem with the .com, so they do not have any performance issues related to serp.

I would really appreciate if someone with more experience could give me some advice on the right solution to handle this situation.