Frequent tense muscles on head. Concern!

Hello, I have been experiencing frequent tense muscles on my head whenever I try to do any mental activity like doing office work or playing a game on mobile. Sometimes they become so tense that I feel like loosing my balance and sometimes my head/torso moves too and fro a litle with my breaths. I have become very sensitive to sharp sounds which gets me startled. Apart from that i feel very tense and some pain in my upper left chest. Even though I had done ECG and 2D ECO test which came out normal I feel like I am going to have heart attack Or might miss my beat. I feel depressed most of the time like brain fog and my anxiety is always under the surface which can get activated by any small things Please guide me whom should I concern