As a native chinese speaker, to learn korean is difficult for me as well, even though there are some similar pronunciation.just like the chinese word ''男票'' which means boyfriend, and the pronunciation of "男票" in korean (a little bit difference exactly, in chinese is ''nanpiao'' in ''korean'' is ''lanpiao'') means husband or couple. When i learn how to speak french(I had given up already because of the female and the male word ),the similar pronunciation to the english confused me a lot. So maybe learning chinese as a single language will be helpful. In contrast to Korean, Japanese has the similar characters to the chinese which has a totally different pronunciation just like the word "写真". That's why chinese can read some japanese word, but can't understand what they say. And just like the shevelen said the grammer is different, it is a big problem. however, since you have learned korean well, you are able to learn chinese as well. Because there are so many chinese partner in italki. And I believe the chinese is much easier than korean.

if you say it to your girlfriend, and you means I am waiting for you. 我在等着你。 if you say it to you common friend, and you means, where are you. 我在找你，你在哪儿？