It seems you are sensitive and vulnerable and highly dependant on others for love affection and happiness. That needs to be worked on I believe you should discuss your concerns in detail with a mental health professional to gain an insight about nature of problem and ways to overcome it through psychotheraputic techniques

Your symptoms may be suggestive of depression if this duration is more than 2weeks , consult psychiatrist at the earliest.. for detailled evaluation and treatment

Feeling low, having crying spells, sleep and appetite disturbances, and difficulty in concentration and attention are some of the signs of Depression. Consult a Psychiatrist for a detailed assessment. It is likely with medication and counselings the symptoms will improve. If you are feeling suicidal or hopeless consult a Psychiatrist immediately