Need Advice

Here's a little background on me.

- I have very bad allergies.
- I have asthma.
- I have controlled thyroid disease.
- Just recently had double hernia repair (Sept 2016)

Here's what I need advice on:

At the end of October I started experiencing slight dizziness and dull headaches. I went to an ENT who couldn't find anything wrong but sent me for an MRI of my brain just in case. The MRI came back perfect, minus a small cyst in my nasal cavity.

I've seen my primary doctor and allergist and both have said the dizziness and headaches would go away on their own. I was given an over the counter nasal spray to remove the inflammation in my nose which lessened the pressure in my head, however the dull headaches still continue.

My headaches have never been severe. If I had to rate them between 0-10, I'd give them a range between 1-4. They are usually at the back of my head, both sides (sometimes taking turns or at the same time) almost like a vice and at the top of my forehead.

Is this really allergies or something else?