Quite depressed with what I am currently doing need some help

So after reading case studies from people earning thousands from a 11 12 months old site with just 140 150 articles, I feel so much depressed.

I have started blogging in 2020 and my first site was bestskateboardsclub.com which I grew to $50 a month in 8 months. Then the site was hit by google and things started to crumble.

I started another site in the woodworking niche and it did well, reached to $150 with ezoic ads but was hit by the helpful content update and seems like there's some kind of ban on it. No matter what I do the site wouldn't rank at all.

3rd site in birding and again the traffic went to 6k a month and then hammered by google now 30 40 a day.

Please help me!

I wanna do this full time so that I can focus on my studies and complete my PhD too