Recurrent Neck Tightness and Headache.

I started practising spoken English recently, and I experience neck tightness followed by tightness at the back of my head and throughout my head, only when speaking English with people over the phone for about 20 minutes. I feel pressure to speak correctly and find words quickly during conversations. When I avoid English conversations, I don't experience this problem, but I need to practise speaking English regularly to improve my fluency. I am concerned about relying on painkillers or avoiding English practice instead of addressing the underlying cause. I have a history of high blood pressure currently 130/90 and was previously prescribed telmisartan 40 mg. Please help identify the cause and advise me on safe treatment and how I can continue learning English without triggering these symptoms.