I don't think that I am pulling, but still I get a headache when I meditate in the morning.
In your particular case, you are meditating on the wrong thing. You are meditating on divine power, but because your inner vessel is not pure enough, instead of power, an aggressive quality comes into you. This aggression you feel as a headache. So when you meditate in the morning, you should meditate on peace. Inundate your inner and outer being with peace; then you will not get a headache. Peace itself is power; it can solve all your problems.