i had similar thoughts. i'm depressed/anxious, stressed and nervous. but it's getting a lot better these days, since i quit smoking weed, cigarettes and drinking coffee.
i actually tried 5-htp recently and it neither helped my depression, nor my lips. in fact i felt much worse when i took a 5-htp capsule. i was confused and had stomach problems, so i stopped again.
the psychological/neurological component of this condition should not be neglected. i'm sure there is a connection at least for some of us.