Small cracked hole in the corner of lip.

Hi, For last few days I have been noticing something in the right corner of my lip. Which started as a small cracked, now it getting deeper like a tiny hole in right corner or you can say in the joint of my upper and lower lip. It's in the right corner, which is visible only if I open my mouth a little bit. Problems I am facing are as following... 1. Tremendous pain, that makes it near to impossible to eat or drink. 2. Whenever I try to talk, it feels like someone is pushing a needle through my right side of my both upper and lower lips. 3. I am applying borolin and other moisturizers to moist my lips or to heal the crack... but it's not working. 4. I even applied orasore lotion over there, but it didn't worked either. i.e. I am a smoker ... have been smoking for last two months. Don't know what's happening with me. Please help me with your knowledge... as m a moderate smoker, but still I am really scared of it. Is it lethal???