Extreme fatigue/tiredness, chest pain.

I am a 32 yrs male and work with an MNC in a role which requires me to be on the laptop pretty much 8-10 hrs daily. These days I feel a lot of fatigue and tiredness (feeling unfresh and stressed most of the time). I face difficulty breathing and have to really gasp for breath. Recently I've started expriencing intermittent pain and tightness in the left chest and sometimes beneath the shoulder in front. Its more a discomforting feeling than a sharp pain. Surprisingly, whenever I exercise or go for a walk, I find the pain getting better. I've been having ashwagandha (half tab in a day, almost daily) for last 6 months or so which helps relieve stress and anxiety. Almost dependent on it now as days I dont have it, I feel more fatigue. Im really confused and worked up as to what issue there is, whom to consult and what tests to get done. I got stress Echo done in March - all clear.