To lower infamy very quickly, release vassals. Especially those in big regions with lots of low value provinces, such as Scandinavia and North Africa. In retrospect, that really would have saved you there. -2 BB per province released.
You never mentioned your cassus belli in any of those wars. You know, you can take provinces for much less than 4 BB, and you won't take a stability hit, if you have a proper CB. The best one is Holy War. Of course the regions you will expand into will usually be dirt poor, but it is a good, low infamy way to expand nonetheless.