It does not state anywhere in the bible that suicide will condemn the person to hell.
Jesus said: '"I am THE way the TRUTH and the LIFE. No-one comes to the Father but by me." Read the 14th. chapter of John. Christ took on the weight of the world. I'm certain he knows depression quite well. Christ would never condemn you for feeling sad. He cries with you.
I would suggest that you learn more of why you are thinking about this and have a good talk with a Minister or Pastor about you faith...or lack of. This REALLY helped me.
A minister who I did not even know saved my life many years ago.
m.b.