Thank you for your question. I agree with my colleagues bellow. You should see your dentist first. Many injectors will attempt Botox, fillers, but it is best to address the underlying cause.
Fat grafting is one of the solutions to make your lips fuller permanently. The trick is that they do not stay as full as they are right after the procedure since fat dissolves so after some time your lips will shrink by 50-70 %. Usually with fat grafting is better do build it up slowly, start...