[bobthechef]

Aristotle and Aquinas are indispensible (though you might want to begin with commentaries or approachable introductions, like Feser's). Contrary to the liberal tradition, "freedom" is understood as self-mastery not uninhibited indulgence of the passions which leads to misery (hence the Augustinian observation that man has as many masters as he has vices). Aquinas also distinguishes beatitudo from felicitas. You also have the virtues. Happiness is ultimately teleological.

Look to the ancients and medievals that we so eagerly forget and dismiss because we think we've unquestionably outdone them. Be careful, though, because your fallacious presuppositions may get in the way. They did for me, but with time, those vicious usurpers, that bad metaphysics, that poor substitute for properly understood science, has given way to a sounder picture of things dislodged from the tyrannical grip of error.

All that is to say that you should not be surprised if you find yourself reacting with incredulity until you begin to realize how unfounded and even incoherent it is. Give it time.