Yes—this is often fixable, especially since you shot RAW. You may not need to manually match every frame. Panorama stitching software can often align the images and automatically blend exposure differences between overlapping frames.

Programs such as newer versions of Photoshop (CS4 and later) can blend exposure seams during panorama creation, and Hugin is also known to compensate for exposure variations.

Because the files are RAW, you also have extra latitude to recover highlights/shadows and make manual exposure adjustments before stitching if needed. But in many cases, the stitching software can handle moderate differences on its own.

So the practical approach is:

1. Try stitching in software that supports exposure blending.
2. If needed, make rough exposure corrections to the worst frames first.
3. Re-stitch and check for visible seams.

For future panoramas, consistent settings are often preferred, but forgetting AE lock does not automatically ruin the pano.