Asking for guidance with a constant migraine and negative test results

[tonirhiann94]

Hi,
I used to suffer with migraines quite badly. I'd get a few week and they would be completely debilitating. After a few visits to the GP, I was diagnosed with anxiety and depression and given sertraline as he thought the migraines were due to stress. I was doubtful, but it significantly reduced the amount of migraines I would get - down to 1 or 2 a month.
However, in march 2017 I developed a persistent headache. Some days it would be mild (around 2 or 3/10 pain score). Other days it would wake me up and would be severe enough that I'd have to miss work. This persistent headache didn't respond to any of my usual treatments and pain-killers didn't help in any way. I also started experiencing other symptoms - extreme exhaustion, nausea, loss of appetite, pain and swelling in the back of my neck, general body aches and a low fever.Again, I visited my GP a few times and had various diagnosis threw around , including: the common cold, a viral infection, pharyngitis, a throat infection, the flu, my depression causing it etc.
On Saturday 3rd June I woke up in agony. The pain was the worst it had ever been, a good 9/10. I also had photophobia and phonophobia. I spend the entire day in bed, curtains and blinds closed, sunglasses on and a blanket over my head hoping it would go away. It didn't. The painkillers didn't do a slight bit of difference either. I couldn't get an appointment with my GP for two weeks, so rang the NHS 111 service to see if I could get stronger painkillers.They were very concerned with my symptoms and sent an ambulance. I tried to refuse, stressing that it was a waste of resources, but 4 hours later I was being taken to A&E.
To try and make this long story shorter, I had a plethora of pain meds to try and stop the pain. Morphine, tramadol, codine etc. Nothing worked. I spent 4 days in hospital, had blood tests, urine tests, a CT scan and a lumbar puncture, which all came back normal. As they couldn't find anything wrong, I was discharged this morning and given a mixture of Tramadol, codeine and naproxen to reduce the pain.
I'm being referred to a neurologist to get an MRI because they noticed an abnormality on my CT which could be an arachnoid cyst. However, every medical professional I've seen has stressed that it's impossible for this to be the cause of the headaches.