Cool story. Next time, after you come back from, play HS, then go to they gym and transform your emotional pain into physical one. Cheers!
Because it was a different meta… ?
I mean you can just look at the data yourself, no priest deck has above 50% win rate outside of bless priest.

5 health is nothing with the tools we have
That’s simply false. There’s a world of difference between starting with 35 and 40 health. This nerf is the entire reason aggressive burn strategies popped up over night. Renathal is generally not considered worth running anymore in almost every deck that ran him before because a 5 life buffer is not enough to justify reducing your draw consistency by 33%. This isn’t some small nerf, Renathal’s ability had its power cut in half.

But it doesn’t mean that Priest was good, but Priest just has the tools to keep the oppressive rogue deck in check and when it got nerfed, priest was bad again, because there were no need for a control priest.
Welcome to control decks? This is how they have always worked. Control decks are only ever good depending on the field they are played in because they are reactive in nature. Priest was good because of the favourable meta, but it was still good. It also had far more good matchups prior to the Renathal nerf (particularly the Quest variants, which were favoured in 12 matchups, 10 more than post-nerf). Losing 5 health with nothing to compensate has (obviously) hammered the win rate of Control Priest across the board.