Week-long headache

Hi, I'm sixteen, female, 5'6", and 140lbs. I take pristiq daily for depression and anxiety. I wear prescription glasses and contacts, but my prescription hasn't changed significantly in the past few years. I have a history with headaches and migraines, but I noticed I was having less headaches for at least a month. I have been having random bouts of nausea at least once a week for a month, though. Now, the past week, I had sun poisoning and ended up in the ER for severe dehydration. It started as nausea, vomiting, and a headache. I thought it was just one of my bouts of nausea, but they haven't led to vomiting. The vomiting lasted about two days. It was mostly nausea and a persistent headache. The day I went to the ER, my neck started hurting, and I noticed significant pressure in my head when lying down. My neck wasn't stiff at all. I could still touch my chin to my chest, and I still can. I received two bags of fluid at the hospital. They put zofran in my second bag, so I felt like I was all ready to go. It's been four days since, and I still have a headache along with just a bunch of pressure in my head. My eyes feel weird. It feels like my right eye is drooping, but it's not, and I can move and feel that half of my face just fine. The nausea is gone for the most part. I see my physician this week, but I just want to know what other doctors think.