What Causes Tunnel Vision, Weakness And Headache?

Hello I am a female 32 years old. when i woke up last night to get a glass of water my vision became tunneled and then almost completely black for about 2 seconds. I became weak, clammy, cold and sweaty. i went into the bathroom to see if i could notice anything different and when i looked in the mirror i was very pale and my lips had a greenish tint to them.
for about the past week i have been waking up with a really bad headache around my ears and as the day would go on it would go away but i would still feel bad.
What do you think happened last night?