What's going on with these random anxious/nervous surges through entire body?

Changes: Are you experiencing any new stressors? Sleeping ok? Or, have you been through a period of great turmoil and things are going well now? Either situation can lead to a great deal of anxiety.

It sounds like panic: Panic attacks can manifest this way. Not necessarily deadly but highly uncomfortable. Need to rule out possible physical concerns. For example, too much levothyroxine can cause similar symptoms. Call your doctor that prescribed it. You may need to take a blood test to check the thyroid hormone level.