Poor website performance - TBT 61 000ms (PLEASE HELP)

Here are some quick tutorial of what you can do to improve your Performance score:
Implement Lazy Loading for Images and Videos
Use WebP or AVIF Format for Images
Minify CSS, JavaScript, and HTML
Optimize Fonts and Reduce Font Loading Times
Delete unused classes

And a bit more technical
Use Asynchronous Loading for custom CSS and JavaScript
Minimize Use of Third-Party Scripts and Widgets

Good luck with this.