You might like Anna's archive. It isn't a quick way to get heaps of ebooks, but I bet you can download them faster than you read them. Haven't kept up on e readers in the last several years, I'm sure you can find a decent one on your own though. Avoid Amazon on general principles, and the kobo ones have Walmart integration FYI (bad)

Join my Myanonamouse. They have the largest collection of ebooks and audiobooks. It's 100% worth it. You can find nearly any title you're looking for on there. You can only join during a certain weekly window, and have to pass a test that is based on their rules, but it is absolutely worth it, my friend.

Are you open to audiobooks? I find I can listen a lot more often than I can read. There's a few good recommendations already here but for audiobooks, Audiobook Bay is pretty good.

Books https://www.gutenberg.org/ Audiobooks https://librivox.org/

Mobilism dot org and myanonymouse

I've never not been able to find what I want