Hello
I understand your concern
You didnot mention your age.it would have given clue to the diagnosis.
Headache,palpitations,
dizziness can be due to hypertension/phaeochromocytoma/heart related disorders with or without
anxiety disorder.
I recommend you to get your certain investigations done.
Blood pressure measurement,24 hour urinary
catecholamine levels,Electrocardiogram,CT scan head.
You can meet internal medicine specialist in this regard.
Further management will depend upon the cause.
Avoid
smoking,alcohol,caffeinated drinks as these may excaberate your symptoms.
Avoid stress physical and psychological.
Hope this information helps.
Any further query is welcome.