What did you use to originally glass the wing? If you used epoxy resin, just add a piece of cloth over the spot where you sanded through and reapply with the same resin. Do this over all the spots you sanded through. Once this is dry, apply a second coat of resin over the entire surface and allow to dry. Then block sand until smooth being careful not to sand through the glass cloth again. You should never sand over your glass cloth application until after you have applied a second coat of resin. It's no be deal, just replace the glass using your resin to apply, let dry, apply second coat of resin to entire surface then sand. You will never see the patch job after you sand the second coat of resin. If for some reason you can still feel or see the patch and are afraid to sand anymore, prime the wing and then sand off almost all the filler primer with a block. Do not sand by hand, use a block which will sand off the high spots and leave primer or resin in the low spots.
Good luck.