My favourite is: Mystic Prince (available on WEBTOON)
Also, on WEBTOON is a story called ‘Soara Academy’ that also has someone crossdressing. It’s not very angsty since she’s found out quite fast, but it’s still nice:)
(The first 24 are recommended! It’s sort of arranged in order of preference. The historical manhua’s are not exactly the best, but can stil be enjoyable:))
Happy reading!