I am completely disturbed from recurring thoughts of past events which made me to feel guilt and helpless. most of the time I feel Depressed because of these thoughts. I have Fear of fainting, unable to concentrate on my studies, Isolated myself from Dec 2019 and avoided meeting and talking to my friends , feel uncomfortable in public places , difficult to sleep , feel less hunger. I lost intrest in almost everything which I liked before. When I am in public places I start sweating , heart palpitations , shakiness and dizziness. I started experiencing most of these symptoms after a stressful event in past. Do I have PTSD?