What treatment is best for me? I'm constantly feeling hopelessness and sadness, most of the time feeling some kind of pain in heart (not physical pain). Due to this I've no concentration in work and neither I'm getting interest in work. I'm not finding ha

Major Depression. Get help as soon as possible. Do not wait. Call PCP or Psychiatrist ASAP.
Agree w Dr. Berger. Your Dr can assess for mood disorder & causative underlying medical conditions. Talking therapy (Cognitive Behavioral Therapy or insight oriented psychotherapy) is allows for lasting change. Psychiatric meds may be indicated. Don't isolate. Spend time w people. Use your support system. Get out. Get at least 8 hrs of sleep/ night & eat healthfully. Daily aerobic physical activity is a big +.
Counseling. These are very serious symptoms consistent with depression and I recommend you seek medical attention promptly! Try to connect with supportive family and friends to help you through this period and realize that you are valuable and that there is help to get you feeling better! There is a great TED talk I would also suggest you see: http://www.ted.com/playlists/175/the_struggle_of_mental_health.
You . You are suffering from depression. You need to seek help from a mental health professional for evaluation and treatment. There are many drug therapies that can help with depression along with counseling or a drug free plan if you prefer. If you ever feel like hurting yourself and have a plan to do so please call 911 or go to your local emergency department. Please seek help right away. I wish you all the best.