What Leads To Sudden Dizziness,blurred Vision And Loss Of Consciousness?

Yesterday I became dizzy, a little confused and felt the need to sit down. When I was unable to do so I lost vision my head turned up and to the side and started to shake. I remember my daughter asking for help and holding me against the shopping cart as she was afraid I d fall. The last thing I remember was thinking my neck was going to break my head was turning so much and I couldn t control it. It then went blank for I don t know how long, my daughter says what seemed like 2-3 minutes and my head and neck relaxed, my hearing and vision came back. I looked around and was able to remember where I was and thought it unbelieveable I was still on my feet. The store manager offered to call 911 but I felt tired but ok. My daughter drove me home. My husband says it s because I don t eat right. I will be honest I had a donut for breakfast and orange chicken for lunch. I am a 54 year old woman about 20 pounds overweight. I have no history of heart problems or diabeties however I did have a non-malignant brain tumor when I was 14 years old. I m a bit nervous. Thank you.