Depression

I think I have depression..I took a checklist on assessing if I have the illness and I answered yes to all the followings.

1. felt worthless?
2. felt sad, down and miserable most of the time?
3. lost pleasure or interest in most of your usual activities?
4. lost or gained weight OR had a decrease or increase in appetite?
5. sleep disturbance?
6. felt slowed down, restless or excessively busy?
7. felt tired or had no energy?
8. had poor concentration OR had difficulty thinking OR were very indecisive?
9. Had recurrent thoughts of death?

I am isolating myself from everyone. I want to speak to someone, but I can't do it at the same time. What really am I supposed to feel and think? I just feel so lonely and tired.