help with plotting with error bars with fit

hello,

i can not succed to do a simple thing

1.do a fit of some values x, y

2.have the error bars

3.plot tougether the fit with the corresponding error bars

i am getting the plot where the error bars are connected by a line so i get two lines with error bars (the line from the fit and the line from the error line)

figure
hold on
Fit_1=fit(X,Y,'poly2');
 plot(Fit_1,X,Y);
hE_1=errorbar(X, Y, err_1);

i am getting something like this:

also any easy way to add the correct legend? as i would like to note only the error bars and the fitted curve with the same color and name it in the legend (in total there are 9 polynoms and the 9 corresponding error bars..)