It's definitely related.
Well, there can be anything happening to almost nothing. It's really normal for someone of pcos to feel like this, however it might also be some sort of disguise for a hidden illness that is slightly deadly or may turn deadly.
PCOS and fatigue are both linked to an imbalance of the endocrine system. Loss of appetite can be the PCOS. You should go to a doctor, please, and get it checked out. Your life is worth it.
Welcome to the MedHelp forum!
Basically you have secondary amenorrhea or absence of periods/menstruation due to some thing. Stress and anxiety is a major factor. Thyroid problems and abnormal levels of FSH, LH, prolactin, androgen hormones or male hormones and estrogen hormones too can be the cause. MRI of brain may be required to rule out pituitary tumors secreting prolactin. Another major contributor is polycystic ovarian syndrome (PCOS). This can be diagnosed by a CT scan or abdominal ultrasound and tests for insulin resistance. Smoking is also often associated with secondary amenorrhea and can be worse in presence of stress. Sometimes tumors of the ovaries and brain may also cause absence of menstruation. Severe anemia and malnutrition, excess weight gain or weight loss, hypothyroidism too can contribute. If you have been on pills or depot shots then this can be post pill amenorrhea.
Do discuss this with your gynecologist (consult another if need be) and get yourself examined. Take care!