Yes, it is possible to develop permanent lung damage after a bout of Sepsis, especially sepsis that was accompanied by a condition called the Acute Respiratory Distress Syndrome or ARDS. There is an extensive medical literature on the sequelae of ARDS, not necessarily limited to the lungs. The following, that you may want to recommend toyour doctor is a good summary of the long term complications of ARDS:
Recovery and Long-Term Outcome in Acute Respiratory Distress Syndrome Critical Care Clinics - Volume 27, Issue 3 (July 2011)
Given that, it is important to keep in mind that your abnormal lung function test may or may not be related to the episode of Sepsis. For example there is a condition called Alpha-one antitrypsin Deficiency that can lead to early onset COPD, especially in those who smoke cigarettes.
At this point the most important thing is that the diagnosis of your lung condition be accurately established. That is, is the condition primarily due to Obstruction to air flow (COPD or Asthma the prime examples) or to Restrictive lung disease, an example of which would be pulmonary fibrosis. The optimum therapy for these two conditions (obstructive or restrictive lung disease) could be very different.
I suggest that you would be well served by seeking consultation with one of the lung doctors who provided your care during the episode of sepsis. He/she would be in an excellent position to evaluate your current condition in the context of the sepsis experienced two years ago.
I hope that whatever is going-on with your lungs is readily diagnosable and reversible.
Good luck
Thank you very much for the information you provided,
I shall see if I can get an appointment with the Doctor who saw me for sepsis.
Thank you again,
Me