Insomnia Support Group
Insomnia is a symptom, rather than a disease, and is characterized by inadequate quantity or quality of sleep. People with insomnia complain of difficulty falling or staying asleep, which results in significant impairment of daytime functioning. Insomnia is categorized as transient (shorter than one week), short-term (one to three weeks) or chronic (longer than three...

Because you are sleepwalking with serious injuries this crosses the line from insomnia to a legit sleep disorder that should be treated by a doctor.
Once you feel the reassurance you are being properly treated, it will help you let go of some of the fear you are experiencing. That tends to help improve sleep.
Night terrors are something else. Those are typically experienced during non REM sleep, and while disturbing, are considered harmless. But your doc can advise you on this as well.
Good luck, keep us posted if you have more info or questions.