i tried so many things and still not visible.
that's not good. SEO is about fine-tuning (where and when appropriate, not always) single (but correctly identified as being the culprit) elements of properly implemented SEO principles (site structure and topicality, technical elements, site speed + navigation + mobile friendliness, etc..), and then let them do their magic.
When you try many things at once (without knowing what the problem is) there's a big chance you'll destroy the things that work without you even knowing, so I don't recommend that you do many things at once again
what can be a problem about this
that's hard for us to say without knowing the situation of your site.
Now, I've never owned news sites before, so I'm probably not the best person to give you advice, but until someone answers that knows better, I think we could start by addressing these questions:
1a) how much content does your site have?
1b) how frequently is the content published?
1c) is the content backed by traffic from other sources?
1d) is the content fully AI, or is it manually edited? (although, I'm not sure that generating news using the AI is a smart idea)
1e) did you optimize your content with stuff like meta tags, LSI terms, SEO entities, catchy titles, schemas, etc? These are important, I think even for news sites, so you don't want to skip on them
2) how old is your site? (new sites tend to stay in limbo / sandbox for months before they get traffic, so this question can be very important, and might actually tell us everything about your situation)
3) is your site in Google News already? I've heard that GNews is very important for google to rank you, so if you're not there you probably want to make this your priority...
I think these questions are enough for now. If you want to answer them it could help us help you (assuming that you've not already screwed your site first by "trying" all of those things that you've mentioned
If you don't want to answer them, no problem! And let's hope that someone who does news sites can jump in with a tip or two...