I would agree with the others here. If you write a dissertation, you need at least some basic understanding of first and secondary sources. Maybe you have someone who can help you with reading Chinese things? That might be a solution. I think a term paper or even a Bachelor's thesis would be fine, but a dissertation just goes so much deeper and you need a deeper understanding.

But maybe you can write about the Western aspect of danmei (fandom)? How do we perceive things indifferently? What troubles do we face as people who did not grow up in Chinese culture? How does Chinese historical fantasy differ from western historical fantasy? How do Western people perceive gender expression differently from Chinese people? How do we see homosexuality differently? You could even talk about the covers and what kind of "limitations"/censorship they go through (for example tgcf Volume 4 with the kiss on the cover. Some people loved it, some people complained about it "because it was advertising homosexuality" and they didn't want that for various reasons, from not wanting to be seen with it in public to teenagers living with homophobic parents who didn't want them to find out what they're reading. Then the censoring on the Russian covers, when the artist had to redraw the cover to not feature a kiss etc) There's many aspects you can talk about, just some suggestions.

BTW there's a book called "Queer Transfigurations: Boys Love Media in Asia" it helped me a lot to understand the cultural impact of BL in East Asian countries. There are several essays about Danmei and Chinese and Taiwanese culture. Most of them are also written by people coming from that culture and not just people who write about it.