Oil filter issue!

Glad to hear it. I'm kinda going through the same thing right now. Had to take my 90* adapter off to get my headers on. No gasket under the bolt or the adapter but never leaked (don't ask me how). Put it back on that way and it pisses everywhere. Although I did angle it slightly different. So I have to wait for the gasket kit to come in. Always something stupid that holds you up.
Look at it closely, when I peeled mine off, it was like a neoprene gasket and it was shaped like a steering wheel. center gasket and outer gasket were hooked together by three spokes. couldn't hardly tell it was there. Make sure it isn't still stuck on there when you put it back together.