Hey...um... i don't know if i am a cutter... i have only cut myself twice and this may sound weird but it makes me feel better. I am a christian... and i know it makes God mad but... it helps me cope. I am not sure if i need help.
You are a cutter, because that is what cutters do and how they feel. I will tell you that there is something wrong with your relationship with God. I know that because you say you are a Christian yet you are a cutter. You know it is wrong yet you do it. You say it helps you cope, but it doesn't really, it is a dead end road that you better get off of now. You need to confess it as a sin to God and ask for His forgiveness.
Have you ever thought about why it makes you feel better, or why you do it? You have to go to God's word to find the answer. You were created in the image of God and if you are a Christian then your body is the Temple of the Holy Spirit. Satan knows that and he hates you for it. So he tries to get you to do things which you should not do. Let me quote a couple of verses to you.
(1 Corinthians 6:19-20 NIV) Do you not know that your body is a temple of the Holy Spirit, who is in you, whom you have received from God? You are not your own;  you were bought at a price. Therefore honor God with your body.
(1 Corinthians 3:16-17 NIV)  Don't you know that you yourselves are God's temple and that God's Spirit lives in you?  If anyone destroys God's temple, God will destroy him; for God's temple is sacred, and you are that temple.
Can you honestly say that cutting yourself is not doing damage to that temple? Are you honoring God by cutting your body? Do you realize that there was at least one cutter described in the Bible? Let me give you the passage:
(Mark 5:1-5 NIV)  They went across the lake to the region of the Gerasenes.  When Jesus got out of the boat, a man with an evil spirit came from the tombs to meet him.  This man lived in the tombs, and no one could bind him any more, not even with a chain.  For he had often been chained hand and foot, but he tore the chains apart and broke the irons on his feet. No one was strong enough to subdue him.  Night and day among the tombs and in the hills he would cry out and cut himself with stones.
Now I am not trying to say that you have an evil spirit, but I am saying that this is the work of demons. I don't know what else is going on in your life, but I will guarantee this is not the only thing. You need Jesus to help you, and you better put Him first in your life. He will help you cope, but cutting is not the answer and it is also not the end. This will get worse unless you take it to God now and confess it and ask Him to forgive you and help you.
I want to just make sure you truly understand what it means to be a Christian:
We have all sinned in our lives. God is holy and demands death for anyone who sins. (Ezekiel 18:4 NIV) For every living soul belongs to me, the father as well as the son--both alike belong to me. The soul who sins is the one who will die.
We are all under a death sentence from a Holy God, who can't stand sin and we have all sinned. Now for the good news. God loves us and does not want us to go to hell to be punished for our sins. Because He is Holy He can't just forgive and forget our sins, His Holy nature demands that some one pays for those sins. (John 3:16 NIV) "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life."
(Romans 5:8 NIV) But God demonstrates his own love for us in this: While we were still sinners, Christ died for us.
If we die without getting right with God we will go to hell for eternity and suffer in punishment for our sins. However, if we will believe that Jesus is the Son of God and that He died for our sins, and if we confess our sins (admit them to God) and ask Him to forgive us He will. And if we believe that after He died God the Father raised Him back to life then we will be saved and if we die we will go to be with God. (Romans 10:9 NIV) That if you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved.
I did not say all that to insult you, but to make sure you understand that you are only a Christian if you have Jesus Christ as your Lord and Savior. Let me show you a couple of other passages that will show you what I mean:
(1 John 2:3-6 NIV)  We know that we have come to know him if we obey his commands.  The man who says, "I know him," but does not do what he commands is a liar, and the truth is not in him.  But if anyone obeys his word, God's love is truly made complete in him. This is how we know we are in him:  Whoever claims to live in him must walk as Jesus did.
We know we are Christians if we follow His commands. You made the statement that you know it makes God mad, yet you do it. That should be a red flag for you, telling you that you need to check your relationship with God. Here is another one:
(Hebrews 10:26-27 NIV)  If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left,  but only a fearful expectation of judgment and of raging fire that will consume the enemies of God.
I am not trying to scare you, but I am trying to convince you that you need to go to Jesus and talk to Him. Ask Him for help and forgiveness. He will help you, if you are willing to go to Him.
E-Mail Ralph (Whose comments are in green)