Dear Shawn Devaraj

Yes dear, unfortunately obtaining new data with a finer step size is the only solution. i enclosed a link content the same problem you faced. if you open it, go the menu and chose finding then search for the word (binning) to stand on the same error and solution. Best regards....

https://gsas-ii.readthedocs.io/en/latest/_modules/GSASIIpwd.html

The step size, or the increment of the angle theta, determines how many data points are collected across the diffraction pattern. A smaller step size means more data points are obtained, which in turn provides more information for the refinement algorithm to work with. Therefore, the slow scanned XRD data will help the software produce a more accurate modelling the X-ray diffraction peaks of the sample.

See

Hill R.J. and Madsen I.C., The Effect of Profile Step Width on the Determination of Crystal Structure Parameters and

Estimated Standard Deviations by X-ray Rietveld Analysis, J. Appl. Cryst. (1986). 19, 10-18

Just to add a snippet of encouragement along with the other correct responses: I have experimented with varying step size and count times. If you use same total scan time with smaller steps, the intensity will have more noise. For example, a 1-hour scan with step size of 0.1 degree steps compared to a 1-hour scan with 0.02 deg steps will have much less noise in each intensity. But, the scan with smaller steps - even though it looks terrible - will give much more precise fitted angles and widths.