I think that you should be tested for adrenal insufficiency as soon as possible, as this is one of the more serious concerns that will need to be addressed soon. Addison's(autoimmune adrenal disease) can give you some of those symptoms, and is often associated with other autoimmune diseases like Type 1 diabetes and vitiligo. It is very important that you have this done soon--please contact your doctor as soon as possible about this. If in the meantime you feel unwell with lightheadedness, nausea, vomiting and abdominal pain, please go to your nearest ER as this could signal adrenal crisis(life threatening).
Aside from that, your doctor should also look into heart concerns which could lead to the lightheadedness and low BP.
Take care of yourself.
Thank you sooo much for your response. I will talk to my physician. Now the issue will be if she listens to my concerns. thanks again!!!.