Understandable. Here's what I'd recommend. Spend $3-10 dollars at your local Microcenter or comparable computer shop, and try out a cheap membrane keyboard. Doesn't have to be great. What you need to ask yourself once you get it is - does this cheap membrane offer improvement in your speed and accuracy?

If so, then pursue high-quality membrane keyboards. They'll likely still be a fair bit cheaper than mechanical keyboards. Or if you're willing to spend a ton (and seem to favor membrane), then you could consider Topre keyboards. HHKB2 seems to be a favorite. But they start at $225 and go up from there.

Let me know if you make any breakthroughs.

Edit: There are a few other Topre-based keyboards for sale, doesn't have to be HHKB. FYI. Edit2: For non-Topre, regular membrane, you could potentially check out this option: https://www.amazon.com/Happy-Hacking-Keyboard-Lite2-Black/dp/B0000U1DJ2 but I would recommend the cheap membrane test first.