I am proud of being a Mongolian. (for some reason it sounds more natural to use the adjective)

I live in China. (full stops and commas must be followed by spaces) However, I am very proud to be a Mongolian (sounds nicer). And (it's considered bad English to begin a sentence with 'and') there are some problems. For example, we Inner Mongolians live in China. When we talk to each other we always mix some Chinese into our conversations. And As society has developed, we have lost some of our Mongolian traditions. This is a shame. We have now realised the gravity of the situation. It is said that we lose ten Mongolian words per day. Here are some things we must do: we should subscribe to and read Mongolian books, newspapers, magazines, etc. And We should also converse in our native language.
I am Mongolian and I am proud of it.

(notes: after my corrections it should be 'grammatically correct' but stylistically it doesn't come across very naturally. It doesn't flow very well. I would recommend you learn about more ways to join sentences together, so that your prose doesn't seem so fragmented. However, overall quite good!)

<em>Great read. Every language is worth thousands and thousands of years of culminative human experience. Please make sure yours does not go to waste. Амжилт хүсье!</em>

I am proud of being a Mongolian.

I live in China. However, I am so proud of being a Mongolian. And There are some problems, though. For example, we Inner Mongolians live in China. When we talk to each other, we always mix some Chinese into our conversations. And with the development of society, we have lost some of our Mongolian traditions. It sounds sad, but only now do we realized the seriousness of the situation. It is said that we lose ten Mongolian words each day. Here are some of the things we must do if we are going to stay true to our heritage. We should subscribe to and read Mongolian books, newspapers, magazines, etc. We should also talk and speak* in our native language.

I am Mongolian. I'm so proud of it.

 *Talk and speak? How are they different?

I am proud of on being a Mongolian.

I live in China.However, I am so proud of being a Mongolian.And there are some problems.For example,we Inner Mongolians live in China. When we talk to each other, we always mix some Chinese in our conversations. And with for the development of society, we have lost our some of our Mongolian traditions. It's sounds sad. Now we are realizing the seriousness of the situation. It is said that we are loseing ten Mongolian words each day. Here are some things we must do. We should subscribe to and read Mongolian books,newspapers,magazines,etc.And also we should talk and speak in our native language.
I am Mongolian.I'm so proud of it.

I am Mongolian, and I live in Russia. And we have the same situatian with our native language. We better speak Russian then Mongolian. And when we spaek Mongolian we always use Russian words.