It is difficult to determine with certainty what diagnosis you have. My limited assessment of your situation is that you have symptoms of anxiety and depression. On some occasions you feel very nervous, begin to sweat and experience dizziness. You might have experienced a panic attack. Generally speaking, these symptoms are consistent with an anxiety disorder and possibly, panic disorder.
In an effort to escape feeling anxious, you avoid interacting with others. This is a mistake. That may seem counterintuitive but the avoidance of anxiety-producing situations will ultimately increase your anxiety. Combating anxiety requires that individuals force themselves to endure it and not avoid situations in which it might arise. I understand this might be hard but it is the most effective approach to eliminating anxiety.
Your symptoms of depression include: feeling of emptiness, inability to focus, low self-esteem and confidence, and a history of a suicide attempt. Anytime an individual gets to the point where they have contemplated suicide, it is a very serious matter. You should strongly consider treatment.
I would encourage you to have a psychiatric evaluation. It could help to determine if you have a diagnosable disorder. In addition, you should consider psychotherapy or medication. These issues might be difficult to solve on your own and may require the assistance of a trained mental health professional. Click the find help tab at the top of this page to help locate a mental health professional in your community.
I hope this answer helps you to better understand what may be wrong. I wish you the best. Please take care.