I TOTALLY relate with the second point, I just cannot be at peace with doing useless activities. But in my books, quality leisure activities like rock climbing, reading, talking to a friend, going out on a date, etc all count as productive.
As to being filled with guilt, the solution I've found is to eliminate useless activities from my life.
Filling my life with fulfilling high-quality activities has given me a ton of joy. Late night partying, clubbing, fapping, binge watching stuff. I've cut all that out.
As to meditation, there are tons of amazing articles on the internet and I'm far too new to the habit to be able to write a whole article.
My only tip would be ingrain it into your routine, even if it's only 5 minutes.
Thanks for reading and responding Roshan!