Sounds like you almost killed yourself. Did you have alcohol in addition to lorazepam? And you have a head injury. But now you are up and typing coherently. I would be a bit worried about your head, and a doctor would probably get an X-ray because you could have a skull fracture or bleeding. If you go to the ER, they might think it was domestic violence. If you want to treat it at home, put an ice bag on it. Have your boyfriend call you every few hours to make sure you are not passed out again; that would require a visit to the ER.
The abdominal muscles might be sore if you were vomiting. That is probably not serious.