INFPs can be quite stubborn and unteachable, I know it first hand. In your case tho, I am on your side cause if you dont want to take pills, you shouldnt need to. This's an incursion into your body and private sphere of a higher level than just being stubborn about another persons opinion.
So I wouldnt do it if you yourself feel fine and are doing fine with your life. There might be a chance that the pills would do you more harm than good. I'd only consider it, if you were really messed up and your life, friends and everything are non-existant cause you majorily aint able to conduct any somewhat normal life. But if you feel fine and things are working out for you, tell the pill dealers to go to hell.