Would definitely have a look at the many instruction videos online. Drinking this kind of tea is quite different from the usual tea bags (normally smaller brewing pots, lower than boiling water temp, throwing out the first brew etc).

Also, the dates you see on Chinese products is often manufacture/production date as opposed to expiry date, especially for tea. If you share a pic of the date then I can confirm. In any case tea doesn’t really go bad, just keep it cool and dry.

Trying to find a favourite Pratchett book is so difficult. I love all of the Commander Vimes and Moist Von Lipwig stories. And also Small Gods. And also Monstrous Regiment. Actually I give up, I love them all.

You seem to like citrus and tart flavoured fruits. Perhaps other citrus fruits such as lime and grapefruit, or pineapple would be something you could try.