Firstly i would like to pass on my thanks to all who replied.
I took my bike to the shop and got it sorted the chain was very badly stretched i had to replace the the front rings and rear cassette(worn out), aswell as a few other worn out parts...i freaked at the thought of being bikeless for a few days...but my god what a difference my bike now goes like dream again...i had forgotten what a nice ride it was. One thing i will do from now on is change my chain every couple of months at least.

Richard..i live in Rhayader. My usual ride is over the old mountain road (Devils Bridge) to Aber and back along the main road (Llangurig)....great ride!!!!

Thank you all again for your help....i am off for a spin!!