Hi sui, I am sorry you have these flashbacks. Remember they come on like a wave and then they always recede. Feeling worthless or unworthy is also very common with people who struggle with PTSD. It is important that you find a good therapist to help you work through this, listens well, and you feel safe with. PTSD also presents fearful feelings, the emotional challenges that take place with PTSD are challenges all people struggle with yet the PTSD magnifies. It is also not unusual to have sensitivity to crowded places that are also noisy, so if you are at a loud party with a lot of activity taking place it can get you aroused/hyper sensitive and uncomfortable. People with PTSD are stuck in hyper arousal so they like to keep their environment quiet and safe if they can. Yes, night can be more of a challenge too because it is hard to just shut down when hyper aroused at the same time.

Are you taking medications and seeing a therapist?