I've been biting my nails for several years now and many of the methods I've tried to stop don't work. I've tried using special nail polish, chewing gum, getting weekly manicures, wearing gloves all the time, and using sheer will power, but still, I bite. I really really want to quit the habit, but it's extremely hard. Any ideas?

Edit: forgot to mention I've also tried putting on fake nails, but I just tear them off... it's a serious nail biting problem.