Been experiencing lightheadedness/ dizziness off and on for the past
It seems to be Benign Paroxysmal Positional Vertigo.
Thanks for writing your query.
After reading your post, it seems that you might be having Benign Paroxysmal Positional Vertigo (BPPV).
I would advise that you should get yourself clinically examined and investigated by an ENT specialist and a Neurophysian. Also get your blood pressure and heart rate monitored. Also get ruled out for Cervical spondylitis.
You can take Cinnarizine 25 mg thrice daily for symptomatic relief. Further treatment may include some physiotherapy and head movement exercises, which can be planned after your clinical evaluation.
I hope this is helpful to you. If you have any query, I will be happy to help.