First of all, ignore them, they are probably just trying to say you'll fail because they know that they are going to fail.
If you study hard enough to pass all of your exams, you will prove them wrong and make them feel like idiots, while you have good marks and they have bad ones.
Don't let them depress you because if you are depressed then that will make an impact in your results. Don't let them tell you that your to fail and believe it because chances are you are going to fail if you believe what they are telling you.
Why don't you just tell them that they are hurting you and making you feel the way you are, because they might not know the impact that they are having on you.
Hope this helps
