[Django]-Celery receives tasks from rabbitmq, but not executing them

You did not provide enough info although I think you have problem with your worker pools.

try adding

--pool=solo

at the end of your run command.
it will be like

celery -A proj worker -l info --concurrency=2 --without-gossip --pool=solo

although on production I recommend using gevent as your pool.

celery -A proj worker -l info --concurrency=2 --without-gossip --pool=gevent