Lost. Feel like my skills aren't needed in the market anymore. Don't know what to do anymore

I got my first job fairly easily back in 2017, I joined a fortune 500 company 6 years ago and made my first switch. I was doing well in my job I got promoted every year or every 2 years. People were dependent on me. I worked mostly on Big Data and Machine Learning.

Now I'm back in market, jobless for 6+ months. I never thought it would be this difficult to even land a fresher role after this much experience but here we are. Companies now demand you to be a full stack , know leading front end, backend, platform technologies, all while contributing to open source and maintaining your github.

The mistake I made was I spent all my time building products for the company, I built internal tools to help teams navigate issues whenever I had free time, also it was a stressful working environment , all of my collogues were working 10-12 hours per day, it didnt leave much time for us to upskill to latest tech and code for personal projects.

I dont even know how do I even start preparing, in the interview rounds I gave till now they can ask you anything from everywhere, the rounds are so different from one company to another, there is always one technology or one requirement that I havent prepared for and thats crucial for them. I am so devasted, due to the nature of our projects I wasn't able to adapt new technologies and mostly worked on old tech, there are hardly any jobs related to those.