The solution for you is extended level threshold mod, aka raise xp req for each level to make you stay lower level longer. It also provide an incentive to do low level quest, because you need every piece of XP.
If you are bored of playing through the official route, you can do the adrenaline junkie route by running north road, with the help of turbo and stealthboy (if you gather any in GS). Cazadores are the biggest threat, then Deathclaw. Going this way you can skip a slew of quest in Mojave Outpost, Nipton, Searchlight, Novac, Repcon Launch site, and Boulder City. it make no sense in term of quest, but you have freedom to do it.
Otherwise, shut up. Our OCD is our burden to bear, not excuse to complain~ Find ways to deal with it.
I'm using something of the sort for leveling, I forget what but I'm running a Tale of Two Wastelands setup on my Steam Deck with 385 mods. A significant number of them are weapons mods, and weapon animation mods on an individual weapon basis rather than a pack because I like the work of several different mod authors.
I don't go to Stalker mod levels of difficulty for New Vegas but I play the game on hardcore mode with certain tweaks mods that rebalance the leveling and availability of items. I know the game like the back of my hand and have for years so I replay it less and less frequently in order to let enough time pass for my enthusiasm for the Fallout setting to be renewed. Plus its always fun to return after a year or so and catch up on what the mod community has developed during my absence; updating my mods and checking out new ones is half the fun, though mod testing results in going through the Goodsprings opening a million more times than normal.
I just had to restart yet again yesterday because I saw that I'd missed a handful of mods that recently updated and included significant enough changes to warrant the restart. Right now I have the game looking by far the best I've ever gotten it to, and I'm not using reshades or major overhauls. I tweaked the config file through MO2 to increase the amount, the density, and the variety of the vanilla grass and with the visual mods I'm running it looks amazing, and I finally managed to get the dawn sky horizon to seamlessly change without the intense brightening effect through a combination of mods like Dusty Distance Redone and the Fog Remover, TTW Vibrant Weathers, Desert Natural Realism Redux, Climate Control with the 3D Rain mod, Cloud Shadows and a few others I can't think of offhand.
One of the mods I like the most that came out around the last time checked back in is Real Time Reflections, and the fact it has a patch for B42 Optics is just awesome. I also love that B42 Optics lets you reposition scope sights too. But on my Steam Deck I actually prepared 4 different controller configurations that I can instantly switch back and forth from as necessary, one layout for adjusting the 3rd person camera position mod, one for the scope sight realignment mod, another for messing with things like Armed to the Teeth Redux and the mod that lets your reposition any weapon in first-person mode to get rid of clipping and such when increasing the FOV, while my basic layout one makes use of the 4 back buttons for things like the hotkeys on mods that let you inspect remaining ammo and weapon condition, the wristwatch one (such a great mod), etc.
Anyway I do enjoy the slower leveling that necessitates completing the loop quests, and what I do is fly through them quickly in a kind of autopilot mode until I get to the 188 Outpost and then allow myself to get immersed into the character and roleplaying. Another thing that definitely makes going through these much more tolerable is mods like Sweet Pain NV (the overhaul of A World of (Less) Pain), Mojave Raiders, The Living Desert, and such like. I thoroughly enjoy some of the areas added by A World of Pain, but obviously the original mod is completely insane and ruins the overall experience especially with the many non-voiced acted NPCs walking around with end-game level equipment. But the massive changes and reductions made by AWOLP and then Sweet Pain on top make it so much more enjoyable; stuff like the Powder Gangers cellar hideout beneath Jean Sky Diving for instance, really add to the game and make it possible to go through all that early content with new stuff to discover.