Since your name is Navodya Dissanayaka, I would suggest you take this name as your Chinese name, i.e., 狄雅娜, whose alphabet letters are Di Yana and pronunciation is dí yǎ nà. As you can see, the pronunciation of this Chinese name shares similarities with your birth name.
I mean, the letters di are in your own surname, so are they in this new Chinese name. The letters ya appear twice and the letters na also appear twice. So, I put these ya and na together and put them in the place of a generational name and a given name, respectively.
If you choose 狄雅娜 as your Chinese name, then you will share this surname, 狄, with other Dis, such as, Di Wanwen, or 狄琬雯 in Chinese, an actress from mainland China, and Di Renjie, or 狄仁杰 in Chinese, a renowned official living in Tang Dynasty.
Here is a picture of Di Wanwen.
Here is a picture of Di Renjie.
雅 could mean elegant and it’s a great choice to be used as a generational name. There are other people whose generational name is 雅, such as Angie Chiu, or 赵雅芝 in Chinese, an actress from Hong Kong, and Wang Yajie, or 王雅捷 in Chinese, an actress from mainland China.
Here is a picture of Angie Chiu.
Here is a picture of Wang Yajie.
娜 could be used as a female given name. There are other people whose given name is 娜, such as, Li Na, or 李娜 in Chinese, a former professional tennis player, who won French Open in 2011 and Australian Open in 2014, and Xie Na, or 谢娜 in Chinese, a well-known entertainment show host in mainland China.
Here is a picture of Li Na.
Here is a picture of Xie Na.