It's correct. As the two people above said, the only wrong is that you don't need a comma because the position of "if" is in the middle. But if it comes at the beginning of a sentence, you will need to put a comma(just like this sentence).

The sentence is fine - except you don't need tie comma after "happier."

It sounds fine to me. Your friend came out with you last night, but you had such a miserable time together that you wish that he or she had stayed home. Other than the spacing/ punctuation, I can't see a problem with your sentence.