Amitriptyline or nortriptyline (similar drugs in the same class) are commonly used for post-concussion headache prevention AND they also are very sedating so can help with sleep.

The vivid dreams and insomnia are very common to many of us. We have had several threads on the forum recently about this.

Be sure to check out OTC drug interactions with a pharmacist and/or drug interaction checker like this if you have a lot of meds, especially new ones in play. Things can get confusing very quickly, and sometimes dangerous.
http://reference.medscape.com/drug-interactionchecker