allergies and headaches

I saw an ENT man In Singapore ( I am working here for a year) recently because of dizziness.  I had been sleepoing very badly for about 3 weeks before seeing him.and I also told him about my headaches. he suggested the headaches  could be caused by allergies. I told him since I started avoiding milk and painkillers, my headaches have got better but not completely and I still always have some background headaches all the time. I also told him I am quite allergic to house dust. he showed no interest in my dizziness except to give me some medication which he says will help my dizziness. ( I was referred to him by a GP.)
   he said he would give me medication and then that would help him to decide if my headaches are caused by allergies. he gave me the following for 3 weeks:
1. nasacort AQ nasal spray 240 doses.
2.Racetam (piracetam) 400 mg - 40 pills
3.Telfast 180  mg - 60 tablets. (fexotenadine hydrochlorine)
4.Prednisolone 5 mg - 40 tablets
     I am not happy to be taking so many drugs and have not started on any. My main concern for visiting him was my dizziness but he just dismissed it. I had only mentioned my headaches in passing. I wonder why I should have to take all these medication just to find out if my headaches are caused by allergies. He said that the medication was diagnostic to help him decide if my headaches are caused by allergies! It all sound strange to me for if they were caused by allergies why doesnt he try and find out what my allergies I avoided milk, wheat, corn, yeast, gluten  for a long time but now I am avoiding mainly milk and do take small amounts of the others.
    Please can you help me decide what to do? shall I just forget about all these medication and perhaps see a neurologist? I had an MRI scan done about 6 years ago in the UK and it was normal. Actually my headaches are now liveable whereas 7 years ago they were really bad. My problem right now is dizziness and insomnia for the past 3 weeks.  I do sleep but not enough.
    Your advice will be much appreciated.