Quickness of symptoms

Hi all. When i noticed the first symptoms (in hindsight, it was my foot dragging a bit doing warmup laps ) it all seemed a very slow descent over about 3 years. The last year however seems a very quick descent from a bit wobbly on the foot to struggling to walk more than 100 metres. Is this normal or should i be a bit concerned about the rate of speed of my decrease in basic walking
Naas, Ireland