I'm sorry to hear about the setbacks in your life. From the information you gave, it is difficult to determine what the problem is. It sounds like you are having difficulty taking tests, and you have mental fatigue and poor concentration. There are many reasons why you may have these symptoms and have poor test performance- it could be test anxiety (a specific type of performance anxiety), stress, ADHD (attention deficit hyperactivity disorder), insomnia, learning disabilities, or medical problems like anemia. I would recommend that you visit your doctor for a complete evaluation into why you have fatigue, poor concentration, and poor test performance.
If you think you have social phobia (social anxiety) and have difficulty with social interactions, then you should consider taking an anxiety test to determine your level of distress. Please visit the rest of AnxietyBoss.com for more help and information on anxiety.