The emotional and feelings of the past experiences are known as Flashback or involuntary recurrent memory, this is a psychological experience in which you have sudden re-experiencing of the past, irrespective of the emotions (happy, sad, fearful etc). This memory recalling is an involuntary action without your conscious, which has no relation with your present situation. There are possibilities that you are suffering from PTSD (post-traumatic stress disorder), there are many levels of this disorder. In initial stage is only re-experiencing the past events that makes you feel low, where the next level makes you feel numb and lack of interest in any activity. This can aggravate to next level with sleep problems, irritability, angry outburst and reckless behaviour. Consult a Psychologist who will be able to treat you with therapies. Don't worry, this is not a major issue which is curable.

Seems like u r having an episode of depression presently. Retrospective memory is a feature of depression. It's a treatable condition. Consult a psychiatrist online or in person for detailed evaluation and treatment.