Feel heaviness in head especially in evenings.Two months ago blood pressure had shot up to 200/120.Left retina also partially damaged.Please advise if I need to get a cat scan done?

I would advise you to get back to your doctor.
Best to you

If your blood pressure is high enough to cause vision distortions, then you are experiencing what's called "malignant hypertension". That is classified as a medical emergency. If you can't get to your doctor today, then go to the emergency room. You risk serious and permanent damage to eyes, kidneys and more- including possible stroke.

They will likely give you nitroglycerin to try to immediately reduce your BP. They might give you a scan to look for blockage of kidney arteries, in trying to determine what is the underlying cause.

Severe hypertension which is sudden in onset is also usually a sign of kidney artery disease, or other kidney problems.

This is nothing to fool around with or delay in.