if your Acne is cystic then maybe you should go to a dermatologist and get a perscription of isotretinoin
however since you have facial hair, hormonal imbalance is the most likey cause, as 'deedee' said Polycystic ovarian syndrome is a possibility, do you get bruises easily, and have irregular periods, these are symptoms, this is a very common disease.
if you dont want isotretinoin then i wouldn't take high dose vitamin A if i were you, as this hasn't really been shown to work in studies, except at doses of 300,000iu per day (IT MUST be water soluble as long term doses this high of fat soluble form could be disasterous for your liver) i would avoud it altogether. Zinc is good (80-100mg per day; read my message on the main board.) have you considered pantothenic acid.this helps u deel with pyschological stress and is possibly an extremely effective treatment fot acne
also as u already know a vegan diet doesnt provide enough protein that is y u dont have any muscle.