There is no way to have an objective position on what constitutes "well-being" since by its very nature is subjective.
I fear you have been listening to Sam Harris too much and with his recent melt down he definitely is not someone I would give much credence too.
As far as his neuroscience background there are many far more learned and smarter than him.
The irony is that because you want to remove objective morality from the picture, the very society you are advocating for (Brave New World) is far more oppressive than one that is set up according to objective morality.
The problem is that while you affirm people living "their" truth forces others to conform to a lie because their truth does not match reality. You have succumbed to the power of persuasion and make no mistake this is "power" it is just not by force.
@Scarecrow is a perfect example.