I'm so tempted to say " a week of penicillin, followed up by Viagra as needed", but am not going to go there. If this was a really cheap one then it was probably made for cos play or wall hanging and not much if any actual use. If it was made for use, then contact the maker & see what they are willing to do. If it was made for a wall hanger, then I'd get a file & re profile the tip
& dump it on eBAY and chalk it up to experience. As to sharpening, if it is cheap even if you manage to get an edge, it's not likely to last for long. Gotta ask, how did you damage the tip?