First experience of visual snow

I found this website when searching for information about visual snow. I experienced it for the first time last night.
I was in bed and had to get up to use the washroom. It was dark, but in the washroom, I turned the lights on. When I left the washroom, I turned the lights off and then I saw white fluffy dots all over my field of vision. They continued all the way back to bed and after I laid down. I closed my eyes and this seemed to stop it. Then I opened my eyes again and the snow was still there.
Then the dots became gradually smaller but more of them. The dots in the middle began to look like falling snow and even swirled a little bit as if wind was blowing the snow.
All the while, I could see real objects in the background - but because it was dark it wasn't clear like it would be during the day.
The dots got smaller and smaller until they disappeared.
The entire episode lasted about one minute.
Possible contributing factors?:
1. I got a virus about a month ago that persisted and I developed a middle ear infection from that. The ear infection was treated first with arithromycin to which I had an allergic reaction (rash). My outer ear also became infected and my ear canal was swollen. I was treated with antibiotic/anti-inflammatory ear drops. The drops worked for the outer ear. Inner ear remained infected. I am now undergoing treatment with Penicillin. So far - no allergic reaction. There has been minor improvement in the ear - less pressure, improvement in hearing. I took a turn for the worse yesterday. So possible link to ear infection?
2. I awoke with a bad headache yesterday morning, and last night when I got up to use the washroom, I had another headache. Migraine? I'm not prone to them, but have had them occasionally. I used to get them from chocolate - from my periods - or from bowel problems (constipation). I have past menopause and so no longer get period headaches. I haven't eaten any chocolate since Christmas. I have been having bowel problems lately. My bowels usually act up (become constipated) whenever I am ill or stressed. When I googled "visual disturbances snow" up popped articles on "visual snow" and most of the articles link visual snow to a migraine aura.
3. My worry is that I have a family history of brain cancer. One of my brothers died of brain cancer at the age of 35 in 1990. He was first diagnosed in 1988. I had a CT Scan in 1990 and nothing was showing in my brain at that time. But so did my father have a CT Scan then and nothing showed in his brain yet at that time. He had what he thought was a stroke in July 2012 which turned out to be brain cancer, and then he died in October. My father died of brain cancer at age 89 in 2012. There is also an ancestor on my father's side of the family who died of brain cancer.