How is headache and low blood pressure treated ?

I woke up about midnight with the worst headache I have ever had, I felt dizzy and my hands were trembling. My eyesight was blurred and I felt distanced. I went to ER and my blood pressure was high for me at 135/85. My pulse was 100, I was given pain killer IM and sent home. I felt very cold and shivery. I am a fit 43 year old woman, I don t smoke or drink. But over the last week or so I have had some pain in the left side of my abdomen, blurred vision in my left eye and been suffering from vertigo for a few months even when sitting down. I was diagnosed with very low blood pressure last year. I am 5 10 and weigh 73 kg.