Questions about symptoms im having

Im not exactly sure what is wrong but recently i have short spells where my head starts to ache very badly and my vision either blurs or goes completly black whereas i can't see anything.  Then i break out into a cold sweat and my legs and arms get achy and weak.  
Non experts have suggested it may be diabetes, high blood pressure, or brain cancer.
I would really like to know the cause of this as soon as possible, i am worried.
Thank You.

[Kyrakyra]

You really need to get blood work ups done go to an endocrinologist.  Get medical records and make an appointment.  It is important to give medical history. Keep a record of symptoms date and time so a pattern might be established. It seems weird but the more information you give the medical professionals the better they are equipt to help you, Best wishes and good luck I hope you will get answers and be able to move forward and get help it is hard to be patient when you feel yucky but Keep going forward you will get your answers.