Hi.. is this sentence right:
so I will be patient and don't get sad.
but sir we learned that we haven't to put (not) before verbs!!!!
In that case, go with the second sentence.
As a native speaker, but not a teacher, I can only tell you what ordinary people in the UK say. Most people would choose to use the first sentence even though it might be grammatically incorrect.
In an exam or doing an assignment use the second sentence. In conversation, use the first one.