Where in Taipei can I buy a mosquito net? If not, some kind of soft mesh frabric I can wrap around my face when I’m in bed would do too.
I bought mosquito nets, those fancy ones that hang from the ceiling, at RT Mart. Come in different sizes and colours. I really had to shop around to find them in white or beige. Pink ones were in abundant supply… 
a couple of years ago I found white ones in Carrefour
Ikea - and if the cashier is as absent minded as mine was, it will be free.
I would think you should try to contribute to Taiwan by sharing your scrumptious dna with the locals. But if you want to make the locals take up your slack, well…
B&Q have some pretty cheap ones. Or you can have them custom-made at the fabric market. We got some made for our four-poster bed and to hang down the back of the van when we sit in there with the back door up. Great for the beach!