Severe headache and no medicine working.

I suddenly had pain on top of my head on 26th Oct night and started vomiting. The tendancy to vomit continued even after everything was out. I used to vomit every 15-20 minutes. Nothing would come out. Due to severe pain in head and vomiting, i was admitted in hospital. The doctor gave me many injections for painkiller but nothing worked. I was suggested to have CT scan. The CT scan of head was completely normal. The hospital discharged me stating that it is a neuro problem but when consulted Neuro, he said that every report is normal so it is not a neuro case. Currently I am given Tramadol and Paracetamol combination medicin and ondem for vomiting. The vomiting is somewhat controlled and now only 5-7 vomitings in a day but the headache is very severe and same. The painkiller reduces the pain but again as its effect starts decreasing, the pain returns to normal. The pain is so much that i can't even get up from bed. Can this be a case of gas getting trapped in head? how to get relief?