Good scriptural advice above. Jews who become Christians are often ostracized from their families too. Jesus said he would divide us and sometimes we need to be separated until we become equipped in our faith.
First of all, don't panic, don't be angry at them, they are blind. Pray for peace for them and yourself. Don't fret. Live, experience Gods love and immerce yourself in the WORD. The Holy Spirit will guide you, teach you comfort you ... you are never alone, He abides in you. Fear not. As others said, meet with Christians in homes in small groups for Bible study and fellowship. Your family is playing hard ball with threats. So take a sabbatical from them for awhile. In time they will get over it. They are hurt, angry and afraid for you because they think you betrayed their gods and are in danger. You are more safe then ever before.
When you look at the whole picture and your mind imagines all sorts of things that could happen, it seems overwelming because you can't control everything at once. You have no control over the future. So, take only one day at a time, ground yourself in the morning with prayer for guidance and God's will to be done in your life and believe that it will. One day is all we need to concern ourselves with. Worry won't change anything. If their love is real, eventually they will miss you and you may reunite with them later. Remember, all religions, philosophies, atheism, cults that keep people away from Jesus are of the Devil, He designed them and your family and their religion is under his influence. So of course, when you start getting close to Jesus, Satan sends his forces against you, people will say and do bad things, anything to scare you and discourage you. Put on your armor, the Helmut of salvation, your shield of faith and your sword, the WORD. You are in the middle of spiritual warfare. But again, be at peace, the enemy is already defeated. Just know what is underneath all of what you are going through.