Psychological problems and weight loss.

Im a 22yr old female and I have always been a petite person,i am worried now though because i seem to be losing weight fast and i dont really have an appetite.i dont feel comfortable with this and i look like a child...alot of things go with this.that nobody takes u serious.i was pregnant a year ago but lost the baby.the end of last year my cousin had a baby and when id hold her my brother and her would be scared id drop her and my brother actually said,ure still little.like im a child. even though i had been pregnant before that....i was and looked healthier then,i dont feel like a woman anymore.ive always had psychological problems but the past year it has been worse,and this is the same time the weight loss started,im not treated for my problem at the moment but seeing professional as from next week.can anyone tell me if there is a link between the weight loss and psychological problems?and what can i do to put some meat back on my bones..im really upset and its getting the best of me.thanks