I want to know if adding a comma before the word "before" would be correct or not.
I had been struggling to find partners for three years before I found the best partners who helped me to learn English.
I think it is not possible in the sentence but if you begin with a subordinate clause you have to use a comma as in the given sentence.
Before I found the best partners who help me to learn English, I had been struggling hard to find parterns
If we begin the sentence with a subordinate clause we have to use the comma before the main clause.
If you work hard, you will pass.
You will pass if you work hard.