difficulty driving

I have not started the sinemet yet but I am reassured and shall take it very shortly.
Was doing a bit of driving today maybe for an hour and half in total and not all at once but had extreme difficulty with the right leg and foot, to keep the foot on the acelerator and brake for any period.
The leg seemed weak and unable for the job and the tight muscle at the back seem to go into a knot. I dont like the sound of this and am real worried as I simply LOVE my wee car and I've only been driving over a year and a bit or more. I started late at 53 and it is now my Passion not to mention my way to freedom
ann