I felt similarly before, my take is to gradually add social structure to life. direction can funnel and catalyse energy.

e.g. pottery, crossfit, book club. for me, it was bjj, a world of warcraft group, and a "beer club".

regularly watching and chatting in a small twitch stream could be a start, but beware its parasocial nature

solo activities add structure but social bonds reinforce discipline and motivation. "someone will notice my absence".

In my opinion, what you need is a person (or three), not a book :)

Someone who relies on you, whatever the context, is some of the greatest motivation out there.

Not sure if you're single, but go on some dates. Getting excited about another human being can be a huge boost. You don't need to replace work with other intellectualism (though you certainly can!)