If your question followed the same pattern as the other one you cite, I would agree that there was a double standard. However, in your question you do not explain your understanding of what part of speech 'which' is and how it is generally used, nor do you explain why you think that beginning a sentence with 'which' should or should not be grammatical based on your observations or research. It seems you believe it is ungrammatical, in which case, you need to provide evidence that it is in use, rather than that it is a usage you made up so that you could ask a question about it.
Because you haven't provided any of these details, the question is not answerable by anything but an opinion at this point. You have the opportunity to edit it to include some more details. After you've edited it, it will automatically enter the reopen queue for high rep community members to review.
To be clear, you have no answers posted on EL&U. You have one deleted question and two closed questions. The one question that was deleted was removed automatically for inactivity. The two closed questions were skimpy on detail and did not have a clear question.
You have one question that was closed as a duplicate. That means it was a good question, just someone had already asked it. You have another open question with an accepted answer. I see no evidence of anyone bullying you, but I see a lot of evidence of community members trying to help you and give you information.