I can't give you the absolute answer, but given that you said you had a crash, I would expect that you bent or cracked one of the gimbal arms and it is binding mechanically. Of course I wouldn't rule out a damaged ribbon cable too. A close visual inspection may reveal any of these concerns.
With regard to your options, you can buy parts and self repair, buy a replacement gimbal/camera, or lastly, send it to DJI and let them fix it for you.
Was the crash your fault or a DJI failure? If theirs, maybe they will Warranty it.
Good luck.