Okay so I have given NV at least 4 clean installs, verified integrity (missing one file, but it says its replaced), and looked all over for any solution but nothing works. I can start a new game fine, but if I try to load any of my previous saves on my character the game begins to load, the loading pinwheel makes have a revolution, then the game crashes. I had a lot of mods active, but I had been cutting them back but the game was crashing every twenty or so minutes. Are there any mods that if removed would cause this? If so what mods? Is there anything I can do but start again? Please help.

Have you tried a new game? Either try that or you may be missing a file. You could delete your game and then reinstall it or you could backup your game files. That's all that comes to mind.

What mods exactly do you have?

I can start a new game no problem, and I've done all of that and still nothing I'm afraid.

As to what mods I have, absolutely none now, before the clean install a good bit, YUP being the only one I think would mess with things. But I really have no idea.

That's the dark side of mods sadly. I hate to say this, but your previous saves might be lost. The reason being is your save probably had tons of mods it was relying on. So when you take them out the save has no way of loading up that data. Pretty much you will have to do a fresh game.

The only thing I could possibly suggest is you literally reinstall everything correctly, load up your old save, then disable each mod one by one. Once you disable one mod reload the game to make sure it's still working.

Like I said though, that might not work either since everything is freshly installed. I'm afraid you will have to start a new game completely. Sorry, my friend.

Did you have NVAC? If you dont have it before I'd recommend to download it to see if the problem is resolved.

Were you using any graphical mods? This could be a problem if you couldn't handle it or you could have installed an enb wrong.

Like @TheThompsonBoss said, some of your previous saves are probably corrupted. It is recommend to just start over. Other solution would be reinstall all mods like @TheThompsonBoss suggested, and check if any of your mods missing the master file. Generally, re-texture/weapons/armors mods shouldn't prevent you from loading previous mods so hope that narrows down to where the problem is.

Download nexusmodmanager and fnvedit. First the modmanager bring your mods in the right order to work and after that open fnvedit, that will show you the errors you got that may cause your crashes, so you know i a little more where to search for.
Has the same problem when i bought a new pc and that helped me to slove the crashes.
If that doesnt help you should think about starting a new game.

Try the 4gb enabler to fix the crashing every 20 minutes , this way you don't have to cut in the amount of mods

Also pay attention to mod dependencies because if you disable a mod that others rely on it can cause crashing as well. I tried modding New Vegas one time and found it was finicky as hell compared to FO3.

Another thing the so called 250 plugin limit doesn't mean you'll reach that number. It depends on your hardware. It would help if you mentioned your operating system and hardware specs.

Ah, it looks as if I'll have to start over, especially as CASM has pretty much pushed all past saves away. I suppose a lot of console commands and the like are in my future. Well, thank you all for your help. I was using the 4gb enabler but the 20 minute crashes still occurred. I've yet to reinstall it but I doubt it would make any difference

Many mods that use some kind of scripts could be the cause of crashes .The easyest way to see which one is cousing the problem is trough the process of elimination .Now you dont remember how many mods you have installed ...mhhm there was a some kind of savegame cleaner .It worked for me once .But expect missing meshes and gliches .So better is to start a new game .If you are having problems with the game constantly crashing just got on NExus and top 100 files and you are good to go.