Have a long layover; suggestions on what to do

A little background story, i accidentally booked a different flight than the one I intended to and now my layover is for 19 hours at Bahrain Airport. I paid £420 for a return flight thinking wow this is so cheap and now they’re asking me for 160-170 more pounds to change the flight even though I called them within 24 hours but apparently they have no policy to change or cancel flights without a penalty charge. It was through Carlton leisure. I honestly would’ve paid the difference, but I’m just financially tight right now and there’s my partner’s flight we’d have to change as well

So now I’m open to suggestions on how to make my layover the most comfortable I will have my partner with me. I read somewhere that they have an entertainment area some sleeping pods and also a hotel? What should I do to be able to access these with ease? I have a Revolut card, I’m not sure what that allows me to do. Should I get a priority pass? I don’t know how much those cost so I don’t know if it’s worth it. I wanted to avoid spending too much money, but also have a backup place to just rest in case one of us gets extremely exhausted.
Thanks in advance