You might try giving earplugs another try. I know for me, I had to experiment a bit with different brands to find one I liked, and even then it took some adjusting until I could wear them for long periods without pain.
Sorry that's the only suggestion I have to offer--I feel your pain.
Perhaps I exaggerated a little in their discomfort levels, but they could certainly be more comfortable. The ones I use are Mack's Ultra Soft Foam Earplugs
They never get to be unbearable, but it would be nice to have softer ones. Do you have any suggestions?
How do the cheap foam ones (ex: Mack's Ultra Soft Foam Earplugs) compare to the ones listed (ex: Etymotic Research ER20 High-Fidelity Earplugs)? Are the cheap foam ones worse in any way?
I don't wear them often at work but I do wear these at home, and LOVE them. They are cheap, comfortable and work well. I started wearing them to bed but I wore them at work for awhile when I got a helix piercing, since my over ear protection would rub my cartilage. https://www.amazon.com/gp/product/B08QW4F39C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I've tried the Mack's earplugs too, which are slightly more comfortable and work just as well, but they're a little more expensive.
https://www.amazon.com/gp/product/B0051U7W32/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Both I've ordered a shit ton of, both work super well. I've tried a couple other brands but between these two I've ordered like 20 packages.
I routinely had to try and sleep on the second floor with no acoustic insulation
That sucks man. I use these to sleep sometimes and highly recommend. I haven't had to deal with construction, but I've slept through landscapers and my noisy asshole neighbor.