Thank you for your question. Your light headedness may be due to spina bifida if you are diagnosed with, although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
On the other hand, in your case this could be a panic or anxiety disorder that you have faced during last event and currently experiencing. Cause of such panic disorder mostly remain unknown but in this disorder you may feel symptoms like shortness of breath, lightheadedness, feeling of choking, pain in the chest, nausea, stomach ache, feeling dizzy, tingling or numbness, chills /hot flashes, bounding heartbeat or fast heart rate, sweating, shaking etc. even without any underlying disorder. This disorder needs to be thoroughly assessed by a psychiatrist first since this can occur repeatedly and without warning. Treatments may include psychological and drug treatments, and depend upon extent of severity of symptoms. Most commonly psychological treatment tried is counseling, relaxation techniques and sometimes cognitive behavior therapy. ************** depends upon treating the underlying depressive illness through anti-anxiety or anti-depressant medicines. In addition, try to rest in a dark & quiet room, meditate, have a balanced diet, regularly exercise and avoid taking unnecessary non prescription drugs to avoid recurrence of symptoms. Hope this helps!!
I'm assuming you did not have spina bifida as a child, in particular the open kind, which can cause hydrocephalus or meningitis, which can affect the brain. If you did have that, it's possible an MRI of your brain would show if anything is amiss.
But what I think might be causing your lightheadedness are rather simpler problems. For example, low blood pressure can cause that dizzy feeling, so you should have that checked by a regular doc, normal is 120/80 altho it can go rather lower until it causes problems. Another example is if you are for some reason either not eating enough protein or your body is not breaking down protein properly, this can also cause a lightheaded sensation plus fatigue. Then there's various heart and circulatory problems that can do this, for example if you don't have enough oxygen circulating throughout your body, you'll feel the way you do. Also, some sort of bacterial infection that you are not aware of can do this. Finally, medications of varying kinds can cause your symptoms.
I think you should go to a regular doctor for a complete checkup, blood pressure check, oxygenation levels checked, lab work, look into your eyes and ears, many different items make up a physical, which can hopefully ferret out why you feel so lightheaded all the time. Hope this helps a little. If you've already seen a doc, go to one all over again, perhaps a different one, like an internal medicine physician, they are good with diagnosing stuff.