As per ur symptoms, u seem to be suffering from depression. A detailed evaluation is needed to rule out other issues.

Based on the information that you have provided, you could be having some symptoms of a psychiatric disorder. Stress can affect mental and physical health. Stress related disorders can affect one's performance in studies, job,interpersonal and social life. Excessive Stress can lead to depression and anxiety disorders. Loss of your mom at the age of three years that you mention could be related to some of your psychological problems psycho-dynamically. Certain psychologically traumatic events in childhood can get repressed in the mind and can have manifestations later in life in the form of conflicts, self esteem issues, abandonment fears, sense of helplessness and hopelessness, etc. Negative thinking, crying spells, thoughts of self harm can be symptoms of depression. Different personality types can also have different ways of coping and adjusting with problems. Certain Medications, psychotherapy, counselling, etc can be helpful in a holistic manner for your symptoms.

For whom r u proving to?! To yourself of set goals Or to the people around you?!!! The more you are into proving and seeking approvals and Appreciation  the more us the stress in yr life.

Stress will always be there in this competitive fast world. Any young student has to come under tremendous stress due their academics  and other environmental factors. Your age is also prone for hormonal changes which can cause mood swings. Being without a parent particularly mother is very stressful for any young adolescent girl. But more than that with the description of symptoms you have given you seem to have bodily symptoms, suicidal thoughts, crying spells, staying alone all of  which could be part of depression.

I can understand the pain of loosing mother at such an early stage of life, I think you are undergoing a phase of anxiety and depression which can reduce your ability to cope with stress, you are getting overwhelmed by stress and experiencing burnout, I would advise you to visit a psychologist or Psychiatrist, talking to therapists and taking some antistress medication will help you