If I can suggest a book: Digital Minimalism by Cal Newport

I had a lot of the same feelings you describe here. Reading this and actually making tangible changes to my habits helped me rediscover my love of learning. Ultimately, the solution for me was to force myself to be bored. I set artificial limits for myself when consuming content online (for instance, I use the procrastination features here on HN and I deleted all "feed" apps on my phone, like Reddit).

I found that once I was bored, my free time became so much more enjoyable and it was easier to deliberately work on something.