How Can Severe Depression And Insomnia Be Treated?

Hi, This is Shampak, i am 32 years old, been working in the BPO industry for almost 10 years now and mostly night shifts and i was finding it very difficult to sleep and consulted a doctor for advice, The doctor gave me Zolsoma 5 mg (zolpidem) for 2 weeks but unfortunately i continued it for quite a number of years as without it i could not sleep for days and moreover i was developing constipation, lower abdominal cramps which reached to my testicles too and could barely walk. Then i decided to move on to ALPRAZOLAM 1 MG tabs which suited me better so far. But i always did have a suicidal tendency since my teen age and i have been increasing the dosage of the medicines with every passing day as it is loosing the effect and still getting awake at nights. Night now if i don t take about four 1 MG tab of ALPRAZOLAM, i would not feel sleepy or may be mildly dizzy but still i can do everything like a normal person can do. I am very very depressed and i don t feel happy at all, completely negative thought process, always feel i am a looser and could not give my mom and dad the happiness they deserved. Please help me. Regards, Shampak.