Respected Sir,
I am sorry to hear about your personal setbacks and the resultant symptoms that you have started experiencing. In response to your query, Depression is characterized by a depressed mood throughout the day, easy fatiguability, loss of interest in activities ,decreased concentration, changes in sleep/appetite/activity level along with depressive ideas and maybe even suicidal ideas and all of this persisting for more than 2 weeks. However you have to rule out a variety of other causes before concluding that these symptoms are due to Depression and hence I would caution you against self diagnosis. Since you mentioned a lot of these symptoms, I would have to say that the possibility of you being depressed is high.
Next Steps
Please consult with a psychiatrist at the earliest and get yourself evaluated in detail
Health Tips
You have already had these symptoms for a year, please dont allow it to get any worse