You currently show as having two answers on your account—one from December and one from about two hours ago.
However, in February, you answered a question, and that answer included a sig that linked to your site. Enough people viewed it and flagged it as spam that your answer was auto-deleted.
Given that you were able to post an answer a couple of hours ago, my guess is that the system sees you as borderline. Neither of your answers have ever received an upvote, and when combined with the spam flags, leads it to doubt that you add quality content to the site.
What to do? As others have said, while What can I do when getting "Sorry, we are no longer accepting questions from this account"? is about questions, not answers, it does offer some advice.