May I tell friends or social media about my marriage problems?

Exposing a spouse's faults on social media or to the public is forbidden, but complaining to those who can help is permitted.
Recounting a spouse's faults falls under the forbidden backbiting (ghibah) (49:12), and the Prophet ﷺ censured revealing the secrets of the marital relationship. But scholars make an exception for complaints made to seek help or justice — like Hindun, who complained to the Prophet ﷺ about her miserly husband (Sahih al-Bukhari 5364). So talk to a counsellor, a trustworthy family member, a religious officer, a lawyer or the police. Social media posts can also become evidence that harms you in court. See Counselling.