Whatsapp bugs are getting more strange these days. I tried several troubleshooting steps and finally iOS Restore and then backup restore of whatsapp kind of fixed the problem for other audiences bro. I started suggesting users to not keep important data inside whatsapp and to take it outside if possible.
Before doing iOS Restore try to moderate the overall storage of photos, videos and other static data in your iPhone.
Then you can take backup of full iPhone and perform the restore via iTunes bro.
Then Restore the backup taken earlier and check whatsapp is working or not. Let me know if that helps bro.