Gonna kinda rant so pls forgive me: I had taken an oath to Allah about a week ago that I would not look at/watch haram, something I really struggle with and am trying to stop. I was studying and ended up on Twitter looking at some graph. I started scrolling and waswasa got the better of me and I started to look for haram pics just by scrolling. I saw one haram pic but didn't look directly at it out of fear. I clicked into the replies and kept scrolling and saw a nasty gif for just a second, so I immediately looked away, closed the tab, said na'thu'billah and istighfar. I got up immediately, opened the Quran, and started reading from it where the ayats I read were about rejecting the signs of Allah, being a kafir, and about how in the akhira there will be no safe haven for rejecting Allah. In that moment it dawned on me I had made an oath to Allah to not commit such a sin.
How badly have I messed up? Also, is the oath broken since I forgot? Should I pay Kaffarah?
Just for extra context, I've been struggling hard with this sin for a while. I stopped watching for a decent time but relapsed recently. I would watch then make istighfar, then would repeat it and make istighfar and tawbah for about a week. I made that oath and stopped for about a week until now.
Please, any advice would be really appreciated.