Hi, this is Dr Sathya. Thanks for your question and I am very glad to help you.
Yes you are right that the blood pressure changes (especially low blood pressure) are important causes for dizziness however there are many other conditions too that can cause dizziness.
The following is a list of the myriad causes for dizziness;
Medication side effect
BP (Blood pressure) changes (either low or high) - appears to be normal in your case
Hypoglycemia (low blood glucose)
Decreased blood flow to the brain
Autonomic nervous system dysfunction
Structural problems in the brain
Inner ear dysfunctions
Stress induced etc
I am not telling that all these above conditions are applicable in your case; I am just providing a list based on what we see in our clinical practice.
And blood pressure being normal it is lees likely the culprit in you however ideally it should be measured in 3 different settings - in lying down, sitting and standing positions and this way BP fluctuations can be assessed thoroughly - and a condition called as orthostatic hypotension can be ruled out too. In this condition the BP drops when some one is in an upright position like sitting or standing and this causes dizziness.
You will now actually require a thorough evaluation in the clinic including a detailed physical/heart/neurological examination & BP checking in 3 positions, and after that you may also require certain relevant investigations to arrive at a precise diagnosis and once that is accomplished then it will be treated appropriately.
You may please discuss all these above points with your clinic-Drs for the further needful (as discussed above).
Please ask me if there are any further questions.
Thanks for the waiting!
All the best!
If you have any additional questions, concerns or clarifications then please let me know. And if you are satisfied with my answer please accept it so that I will be credited for my expertise, time and effort put in preparing this answer.