When using breathing techniques in meditation you can sometimes need to be careful. I have a technique called Lama Yoga it is a breathing technique but you need to be careful using it. It is good to have a guide with you to make sure you don't past out or get too much energy going to handle.

Do you have someone there for you to watch for you or are you alone?

It would seem by your description that your kundalini is blocked at your Ajna chakra, you are trying to force it through. Do not force kundalini energy through a blocked chakra you can be very sorry that you did if you do.

Instead you would need to clear that chakra gently by letting the energy settle back down. Then work on your third eye with love, if you know reiki that will help. If not you can still hold your head in your hands and intend clearing and healing.

I agree with Wade on this one, but would like to add a few words to his answer.

If meditation makes you uncomfortable, this very first item I would check is your position while meditating. I, personally, cannot maintain the "classic" poses that most people use while meditating. I find that I get my best results while lying on my back with a large pillow under my knees. You have to be careful with this one, though- don't let yourself go to sleep. I would not advise using your bed for this- hopefully, you can use your couch or hammock outside- something like that.

Secondly, it sounds to me like you are concentrating very hard while meditating. This would trigger a headache for sure! Perhaps you need to learn to relax your body very slowly and gently before trying to "go deep"- and perhaps this is really the key after all. You need to trigger specific brain waves, and those brain waves feel very good. Are you trying too hard? Check on this.

Email me if you would like specific directions for a good meditation that I use that really helps me.

Peace!

Jai