Thanks for bringing your question to JustAnswer.
If there is a history of trauma in your background, losing time might be a symptom of dissociation, or Dissociative Identity Disorder.(DID). Dissociation is a coping technique that usually develops in childhood, when the child is helpless in a situation. The child copes by removing herself mentally from the trauma. However, as the child gets older, this way of coping can be very disruptive, as you've mentioned.
Here are the links: As you read, it's important to remember that there are a wide range of symptoms within the DID framework--not everyone develops other personalities.
If these symptoms, or some of them, seem to fit, you'll want to see a counselor who specializes in DID or trauma. Here's a directory to help you find a therapist in your area: