My first real guitar was a Schecter C-1 classic, that had a 1.653" nut width, and neck profile of 1st Fret- .787” 12th Fret- .866” (22mm). That's The website specs, but who knows what it actually measures though due to production tolerances. Either way it is extremely thin.
Just like you, it made my hand extremely sore very quickly. I did some research and that other people also found that thin necks cause hand fatigue. So my next guitar was a Warmoth 1 11/16 Fatback. I actually still find this very comfortable! I feared that it would be way too large, but it wasn't at all.
Upon further research, it seemed that people generally find a smaller nut width is more comfortable as well. The only complaint I find with smaller nuts, if it's too small for fatter fingers. I was actually hesitant to choose between 1 5/8 and 1.650. I figured that smaller = less hand movement = more efficient =easier and better playing, and i'll KNOW if a nut is too small pretty quickly. I rather go too small and know 100% that I need to go a bit larger, than go one step down and have that nagging "what if" the smallest option is better. So when I saw that 1 5/8 neck I decided at the price, it's worth a shot.
A lot of people seem to love the 59 profile, so I decided to try that next. Even though I find the Fatback comfortable, I think it's very likely that the '59 profile got it's legendary status because it's in that goldilocks "just right" zone. I know already from my Schecter that the standard thin profile is probably still too thin, and your post confirmed that for me.
It's an interesting note that $$$ Suhr guitars spec a 1.650 nut width, and $$$$$ Collings guitars spec a neck profile (.865 - .967) almost identical to Warmoth's '59. That's why I was really really debating 1.650 and '59 vs 1 5/8 and '59. Either way I'll know my answer soon, and i'll instantly know what my prefect neck specs are!