Chest discomfort, vague feeling,

I am a 30 year male suffering from Allergic Rhinitis and Asthma. My main concern is chest tightness and feeling of discomfort which is more prominent while laying down. I am taking seroflo 250/25 but it isn't relieving chest tightness. I have undergone chest x ray, ecg and echocardiogram which were normal. While laying down for sleep, I cannot keep my body still and I have to constantly move my body here and there to relieve discomfort until I get sleep. Also, sometimes I wake up in the night suddenly with chest discomfort. Could you suggest some other test i.e. CT scan chest, MRI chest or ultrasound chest or some other test to properly diagnose it? Which test will be more appropriate as chest x ray was normal?