Landlord charged all utility bills accumulated over years at once and the sum is very large to pay asap. What are my options?

My landlord sent me all utility bills for my tenancy at once. This is a large amount and I'm wondering if I'm required to pay it all asap?

The tenancy has been ongoing for ~2 years. I've read on the RTA site that the owners are required to notify the tenant within 4 weeks of receiving a bill or payment isn't required. Does this apply for tenancies that started before the changes too?

Thank you for your help!

P.S. There are many other issues too. For example, I've learnt that a landlord is required to lodge the bond with the RTA but mine kept it in his account. That's an issue I'll have to deal with soon as I have been asked to move out