Left side diaphragm weakness, ever since diagnosed with viral infection I cannot get a deep breath

18 months ago one night I suddenly found I couldn't get  a deep  breath. I panicked and went to hospital they said it's probably a viral chest infection and sent home   Ever since that night I struggled to get a deep breath and was getting a lot of urges to breathe in. After  investigations the respiritory consultant  said I have a slight unilateral left side weakness . My symptoms are frustrating as in I am not breathless   And don't get easily out of breath walking climbing stairs etc  just feels like I'm being suffocated. It is slight ly better but I constantly am thinking about breathing  , I better lying down. Which contradicts the symptoms and on an empty stomach. It's worse as it feels like air is pushing on my diaphragm which makes it harder to breath. Iv been told to do breathing exercises and try and strenghten my diaphragm but  it does not see to be helping  ,a get a strong pinching  sensation sometimes in the middle of chest . I'm fine swimming which I was told would be difficult because of the water pressure .  Looking on websites it says unilateral  weakness is nt that serious and will probably resolve itself . It does not feel like this is going to happen  has anyone got these symptoms . Iv been discharged from respiritory for a year   Then they will check my lung function again . I was told about plication  but that it's not that effective , so that was nt encouraging .