I like reading „classical literature“, and I find I enjoy a lot of it more than I expected to. Often I do have to push myself, because it can take a fair bit of concentration/perseverance, but it‘s usually worth it.
However, I do know the feeling you describe: sometimes, it just doesn‘t „click“. And in that case, I will eventually move on to the next book, and try not to feel guilty about it ;-) (I started „Paradise Lost“ twice. I love the absolutely epic poetry and vivid imagination, but I still ended up getting stuck both times...)
I'm a believer in audiobooks as a great way to experience the classics, you don't get derailed when there's a lengthy genealogy or dedication to a long dead patron. It's true to the original experience of the works too since there was much more recitation and reading aloud when copies were scarce.
PS no audiobook version could redeen Paradise Lost for me either, it was my peast favorite reading in high school. To paraphrase, better to be ignorant in hell than well read in heaven if you have to trudge through Milton to get there.
However, I do know the feeling you describe: sometimes, it just doesn‘t „click“. And in that case, I will eventually move on to the next book, and try not to feel guilty about it ;-) (I started „Paradise Lost“ twice. I love the absolutely epic poetry and vivid imagination, but I still ended up getting stuck both times...)