You've already taken the first step by realizing that your outbursts of anger are wrong and do great harm, and that you need to do something about them. The Bible's judgment is true: "An angry man stirs up dissension, and a hot-tempered one commits many sins" (Proverbs 29:22).
What can you do? First, admit that you can't conquer this problem on your own. You need God's help -- and He is willing to give it to you. If you've never done so, turn to Him and admit you need Him, and then ask Jesus Christ to come into your life to forgive you and change you. God wants to help us -- but He won't if we think we can shut Him out of our lives. Open your heart and life to Christ today.
Then ask Him to help deal with your anger in practical ways. Do certain situations make you angry? If so, learn to avoid them -- and when you can't, commit them in advance to God and seek His help. And when you feel anger welling up within you, turn instantly to God and ask for His peace.
Most of all, ask God to transform you from within, making you more and more like Jesus Christ every day. Make His Word, the Bible, your daily companion, and let its truth reshape your life. The Bible says, "Let the peace of Christ rule in your hearts, since... you were called to peace" (Colossians 3:15).