played several games now, and no matter what, the ai always wrecks me with ideology, causing me to get 40+ unhappiness, making end game totally unplayable, something needs to change
I have to agree with the person who commented immediately after your post and presumeably several other people.
If you're going to show absolutely zero flexability and adaptability and dogmatically stick to an ideology and a play style that may have even worked well before THEY CHANGED THE RULES OF THE GAME, then you have to expect that under the new rules, which you can't seem bothered to learn, you do less well.
I never have a huge problem with happiness as I trade extensively, prioritizing the finding and trading of luxuries, I spend a lot of time and effort courting the City States and outright buying them. I even in my second game of BNW took Autocracy because my one neighbor and thus most important trading partner took Autocracy. I basically never took Autocracy in the previous incarnations of Civ and I still do not see it as the best choice, but in some situations such as when your neighbor has to choose between attacking you and Germany and you go out of your way to be nice, to honor deals, to make fair trades, and to even follow the same ideology, funnily enough Carthage chose to attack Germany.
I ultimately won. It wasn't easy. I had to make choices all along the way, sometimes I didn't get to build what I wanted, sometimes I lost out on key hexes to Carthage, but I didn't invade them, there is no Culture Bomb anymore and I bided my time. I made Shinto the World Religion. I got as many delegate votes as I could and slowly while everyone else was busy fighting or trying to win the space race, I squeaked out a diplomatic victory.
I don't think the AI Major Powers have voted once for me to outright win, they also don't like it when you force a World Religion upon them. I have seen the AI's Major Powers vote for someone other than themselves to win diplomatically, but not in BNW. Now with 2 extra votes for losing each election, 2 votes for having the Holy city of the world relgion, 2 votes for following the World Ideology, plus votes from City States you can slowly build up the support you need, avoiding going to war and losing access to all the luxuries that make your people happy.
There are pleny of Ideology Tennants and Social Policies that make your population happy. Sometimes Aqueducts or Granaries or whatever can be made to produce happiness. I think rather than complain the game is broken you need to rethink your strategy, adapt, try a different ideology, try some different social policies, try a different opening, try not expanding quite so much, try trading and staying at peace with your closest neighbour, even if they are an autocrat.
Good luck!