My dear child, does your church have a youth pastor? If it does, please talk with him or her about your thoughts of suicide. If not, either ask your pastor for the name of a Christian counselor in your area or find a church with a solid youth group. Thoughts of suicide require a mature Christian professional to help you. As for your friend, I would really recommend finding more Christian friends to hang out with, and gently, lovingly reduce the amount of time that you spend with this person who is a stumbling block in your faith. If you have other friends who are solid in the Lord you can see where this other person is hurting you and won't feel the need to spend a lot of time with him or her. I know this for a fact because I was in a similiar situation for years. My one regret is that it took years to get away from this person.

Father, I lift this young person up to you. I bind all works of the enemy that are trying to pull this individual away from your plan for their life. We take authority over the spirit of death that is oppressing them. We ask that you lead them to mature Christians who will instruct them in your Word and help them to grow into the solid man or woman of faith that you call them to be. In Jesus name we pray, Amen.