Hi there,
Thanks for your query.
The brief details provided by you, point towards the following possibilities:-
*   Mental stress/anxiety, leading to frequent migraines. A long-term course of anti-depressants + anti-anxiety drugs combination will provide you great relief from headaches, 
dizziness  and fatigue.
*   Thyroid problem (
hypothyroidism) which, in addition to your symptoms, is also accompanied by weight gain, constant fatigue, mood disorders, hair fall etc. Thyroid hormone profile will rule out/confirm this condition. if the diagnosis is confirmed, thyroid 
hormone replacement therapy will cure you of all problems.
*   Fibroid (a growth) in the uterus, which will be detected on 
ultrasound.
Consult your doctor and apprise him of my opinion. I am certain that he agree with me, order required tests, and- based on the reports-  will prescribe suitable treatment as advised.
If you find my response helpful and informative, do not forget an “excellent” rating to my answer, to encourage all doctors- engaged in social service- to render sound advice to the FREE queries. 
Fond regards and have a nice day
Dr. Rakesh Karanwal