renault clio losing power in low gear?

My 1997 clio has been stalling when I come to a roundabout or junction in fact anywhere I need to go into 2nd or 1st gear, I was quite scared when finishing work at 10 oclock at night it stalled on a very busy roundabout, it normally restarts straight away but then the rev counter shoots up to about 40 and it lurches forward.I had problems with it a few month ago where it kept losing power from the battery if it stood overnight and had a compression test and new battery lead,but since the new lead was put on it was fine, but now these new problems have started.I have been told that it may be a problem with the carburetor but I dont know enough to say for sure. I had new oil filter, oil change, air filter ,spark plugs and battery lead a few months ago which solved the problems for then but now this has started and Im frightened that someone is going to go into the back of me. It is a 1.4 and has only done 38,900 miles so I am hoping someone can give a complete and utter novice some advice on whats best done and please dont say scrap it cos I love my little car.