I got one of these a few months back, and it was sharp out of the box. I touched it up a little, and then it was very sharp. With the awkward blade shape, it eventually dulled with me being at a loss of how to sharpen it. I have tried a few different pull-throughs, to no avail. Holding it perfectly vertical while pulling through, the edge on one side is so small I can barely see it, and the other side is about 3 times larger. I can't free-hand it on a stone, and can't afford a stone guide (very pinched for cash, and don't have a decent stone). Any suggestions?