I've found a fantastic solution that works on any phone! Uninstall facebook and facebook messenger. Then use Chrome and facebook's mobile site. Life changer, man.
I haven't had much problem with FB Messenger, and it's app is more useful then the mobile site.
However the main app is a total dog and the mobile site is quite complete. Would definitely remove it.
But then you will not know, what to do with all that extra battery life!