You may have LOW blood pressure. The following are signs and symptoms that suggest low blood pressure.
Dizziness or lightheadedness
Fainting (called syncope)
Lack of concentration
Cold, clammy, pale skin
Rapid, shallow breathing
As you can see, every symptom you have mentioned is on this list. A sudden drop in blood pressure is a reason for concern, and can be very dangerous. You need to make a doctors appt. asap, or visit your ER, preferably someone else driving you due to an increased risk in fainting, and your vision troubles. Rapid dropping in blood pressure can indicate a serious underlying problem such as uncontrolled bleeding, severe infections or allergic reaction. Several medications can cause blood pressure to drop as well. Also certain disorders such Heart problems, Dehydration, Endocrine problems, and Septic Shock can be to blame.
If your symptoms persist, I suggest you call your doctor, or visit your ER right away, this can be serious.
Thank you so much, I wish you well.