Probably not the best approach but if you're in Development and don't care about migrations, go into your migrations folder and the other folder with your .pyc files and erase all those. Then run a makemigrations for that app and migrate again.
This will erase all your past migrations, so if those are important, then don't do the above
It's usually if you're adding or deleting fields you'll end up having to do that. If you delete a field, delete the actual data from that specific field in the database BEFORE deleting it from the model. Otherwise the database will have extra info in it that relates to that deleted field and that causes issues.