If i uninstall dawnguard, will my game revert back to the time before i had the expansion installed?

I decided that I did not want to be a vampire , I want to help the dawnguard, but I do not have a save game from before the start. So if i remove the game data and then start my save game, will i be playing as if I never started dawguard and if i reinstall it will i get to start the dlc all over again? Also if this does work, will i still be stuck in the vampire lord form, or will i be back to normal? If i am stuck in the vampire lord form is there a way to get rid of it?

Uninstall, load game, save game, reinstall should do it.

from what i know the only way around it if you havent started the companion quest line an this is only a guess would be to start their quests until you become a werewolf but i've got no idea if it will work on the vampire lord alternatively you could seek out fallion in morthal an try an take the cure again i have no idea if it will work.

only way i know of making it actually work 100% is to start a new game but you can try the other two options first.

If this DLC put some scripts on your save, then this might not be the best course of events. Removing Mods from a save is bad, DLCs may be also.

If you do remove DAwngaurd,, then make a new Save Slot after and see how the game is. The issues from this may not be immediately seen. For sure, taking the other path on this save, especially if you are a vampire now, is going to mess up. You may have to start a new character or load an earlier save to follow the other path.

The key to playing this game with sanity is to have save slots you can go back when making character altering decisions.