Meditation causing headaches

In the last couple of months, I have experienced a chronic headache in my forehead and after checking with doctors etc nothing could be found. I then kind of had the intuition it could be related to my meditation practice. It's more the 2 years I meditate daily for 20/30 minutes or more. I have come around some articles online reading that focusing on the breath (especially in the nostrils, which I used to do) could lead to an accumulation of energy around the third eye chakra, and it seemed to me my pain felt exactly like this. I have now taken a break from my daily practice and the headache got much better and nearly disappeared, but as I stopped meditating I really miss the peaceful state of mind and presence I had when I meditated daily, so I would like to start again soon. I would be so grateful to get tips from you on this.