I've had similar experiences. Here are practices that worked for me.
First, if you are doing concentration practices, practice zooming out and in between wide and narrow focus. I think that the pressure at chakra points can be caused by an involuntary single-pointedness that remains after the meditation period is ended. I found that using kasina meditation was a great way to learn to zoom in and out my focus. First see the kasina close up then far away. Keep investigating until you find the mental knobs to move your focal point to different spatial depths and different widths. Another option is to do concentration meditation on the soles of your feet, this tends to draw energy away from the head. The danger of doing this with a lower spinal chakra point is that it can start to open the chakra and release even more energy up through the spine into the head. The feet seem to be pretty safe thought. You can also do standing meditation and focus on a point about 6 inches below the feet in the centre (earth chakra).
I also recommend the lessons on self-pacing at
this yoga site. AYPsite.com is sort of the yoga-tradition equivalent of the Dharma Overground in my opinion.
If you want to take a more direct approach to solving the problem, here’s what I’ve discovered works after many years of trial and error. This approach balances the distribution of nervous system energy between opposing muscle groups. To do this, start by noticing the tension in your forehead and while maintaining focus there, bring your attention to the muscles in the back the base of your skull, as well as you temples. These tissues form a sort of headband around your head. Try to relax your muscles in your forehead and notice how this transfers the tension to the sides or the back. Now, see if you can get good at transferring the tension back and forth from front to back (being aware of the sides as well). Don't try to get rid of the tension, just move it around. Finally, when you are quite familiar with how to move the tension back and forth from front to back do the following. Clench your brow in the familiar tension pattern. Form the mental intention to keep firing off those muscles maximally. Then, while maintaining this intention SIMULTANEOUSLY fire off a very strong intention to relax the muscles and transfer the tension to the back. In other words you mentally trigger two equal and opposite movements at the same time. Keep this up, don't just fire it for a second and stop, keep a constant intention for both movements for as long as you can remain focused. Although this involves effort try to remain calm at the same time so you don’t add extra stress to the system. Keep your breath slow and deep. This will take some practice to get down. When you've got it, the contradictory signals to your nervous system will sort of short circuit the whole tension pattern and your entire head might shake a little and feel out of control. You might experience fear, as the you experience and unfamiliar body configuration. Do the practice with somebody else present if you are nervous to try it on your own. After you get a shift that feels like a complete or partial cancelling out of the tension pattern, stop and move your head normally through its full range of motion with your eyes open. Do this several times to help your brain build correlations with the new movements.
Anyway, in my experience this is the most powerful technique for diffusing energetic tensions. Don't over do it though or push too far past your comfort zone. Just work on releasing a little tension every day. It's also normal for the muscles to be a bit sore for a few days after a major release as they adapt to unfamiliar movements enabled by greater mobility.
Good Luck.
Avi Craimer
Meditation Teaching