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...

I also have felt something similar to what you've described in the night. I believe this worried wakefulness and tension in the night comes between sleep stages, and likely just after a REM stage. Many people briefly awaken after one of the several REM stages each night and before dropping off again to a deeper slow-wave stage of sleep. Most don't even remember these brief awakenings by morning.
However, if you are hyperstimulated or undergoing chronic stress, instead of falling back asleep you can go the other way -- toward alertness and worried wakefulness. It's almost feels like a sudden jolt of adrenaline, but I think it really is caused by an excess amount of cortisol in your body ... cortisol being the stress hormone.
If you are chronically stressed, cortisol builds up in your body during the day, and well into the night for many of us insomniacs. That can and will affect sleep.
To help reduce cortisol and sleep better, you might try a concerted effort to reduce stress both through both physical and mental means. Physically through exercise every day. Mentally through a variety of methods -- relaxation, deep breathing, yoga, music therapy ... there are a number of ways to turn down the dial on stress.
You might also be able to identify a number of auto-stressors in your life, and counter these with better response. These are situations that automatically result in a stress response, and they're common. Like a tailgating driver for instance.
It also sounds like you have a number of automatic negative sleep thoughts, and this also can be a significant contributor to insomnia. If so, you would benefit by learning how to identify and replace them with more accurate and positive thoughts that support better sleeping.
A good comprehensive cognitive behavioral therapy for insomnia program will help you with all this. You might look into that. You can learn CBT-I from downloadable sleep training programs that are online, books, sleep counselors, and so forth.
Good luck, please keep us posted on how you're doing.