getting angry

So recently I got really frustrated & angry at myself for the way I look. I cut myself then threw the scissors at the wall & it made a hole in it. My loving boyfriend came in while I was crying & asked what was wrong, I only told him about the wall not cutting myself... What should I do? I feel really bad and last time I told my previous bf about my cutting he threatened to break up with me. I don't want this to happen again... I love him and I trust him but I feel so bad for not telling him. Help please