I have been off and on for the last two years...

how do i go back to normal base?

go to the wardrobe and click on the 'skins' tab. at the top of the list of skins there should be a button that says 'remove skin' which will revert your avatar to the default base. after you've done that, make sure to click 'wear' so your avatar saves. then you can put on or take off any special skins you've unlocked whenever you want.

if your avatar is not loading correctly in the new wardrobe, you may have to convert it; there's a link to do so on the first wardrobe page.