Changi 20 hr layover help

Hev evervone please can you help me plan my 20 hour lavover in Changi airport.

Arriving at 6am on 1st Apri

Connecting flight to london is at 2:40am on 2nd April.

I don't have Priority pass or any credit card access to use lounges- will need to pay if using - which lounges should I use and when? food is my priority as food seems expensive in the airport restaurants

same with hotels - they seem pretty expensive at the moment so anv deals or discounts anvone knows please let me know

Please note I did not book this intentionally - I only booked this route due to the current conflict in middle East as I had limited flight options.