Is there any chart showing total number of new transctions (both confirmed and unconfirmed) per day?
There are various places where you can view the number of unconfirmed transactions (I don't think you can get an accurate number for the total amount per day):
Tradeblock - ~25k unconfirmed transactions right now.
Blockchain.info - ~21k unconfirmed transactions right now.
BitcoinFees21 - Useful for viewing what kind of fees were included (in addition to the recommended fee).
You can use these three to analyze the situation and possibly determine if an attack is taking place.
That's are some handy sites. Never had some tools to verify a actual hack was happening.