Thanks for the responses! These are greatly appreciated.
When my heart was checked with a stethoscope on 19/18/2017, the murmur was heard in the lower left quadrant. So I assume this would be the aortic valve. As indicated in the posting by @srounkle this could very well be the issue. I also have read that this condition is most prominently found in men. I still do not rule out the fact that my joint swellings began at the same time as the shortness of breath. Maybe I contracted some kind of bacteria which caused the valve to malfunction? If that is the case, I am hoping that maybe if that bacteria has stopped then the valve could heal. Also, over the past year my shortness of breath was getting less and less and then over the past couple of months, my condition deteriorated somewhat. Something which happened about two months ago was a very painful toothache and the dentist said the tooth was draining. I have now had that teeth pulled. In addition, I had a return of a painful joint in my thigh.
Overall this currently does not cause major changes to my lifestyle (other than I am unable to jog 6 miles like I did in the past). However, day to day activities are mostly normal. I normally only have symptoms when exercising and not when laying down; no passing out; no visual disturbances. I am currently on no pharmaceutical drugs