I am studying Kant in my philosophy class. I am a freshman in college and I am thoroughly confused by his Critique of Pure Reason. Instincts can get you closer to what you want to accomplish. In a sence Kant agrees with another philospoher, David Hume. So-if the cultivation of reason is required for the purpose, and the purpose leads to happiness.
Reason is infact compatible with happiness.
I don't know, maybe this will only help with the questioning you can give to someone else, perhaps another philosophy teacher. I also found Encycolpedias of philosophy very helpful as i was looking for a better understanding of other philosophers.