You need to undergo some blood tests which can tell us what exactly is the problem. Seems like you are having some hormonal imbalances due to which you are facing these issues. Please consult privately so that I can help you better as it is better to discuss such problem privately.
Hi there....as you know few people have very high basic metabolism rate. It will be difficult for them to gain weight. Also one should remember gaining weight and losing weight is a very gradual process. It will a lot of time, patience and determination. You must follow a healthy diet and exercise schedule. Start having food rich in proteins like pulses, soyabeans, vegetables, fruits, egg whiteboiled , boiled chicken. Regarding exercises, start cycling or swimming, whatever you are comfortable with and enjoy most. Along with it try doing high bar excercises. You can also visit a dietician and endocrinologist for further queries.
Also looks like you could be suffering hormonal imbalance(excessive hair) like pcod. So kindly consult a gynaecologist once for further evaluation