首先你这句话错在两个地方,
一是becomes应该是become,因为句子的主语是"我",即"I",第一人称应用动词原型.
二是翻译可以不要太直白,直白有时反而显得生硬,"和你成为敌人"即是"成为你的敌人"的意思,所以可以翻译成"become your enemy",
第三是句中which 可省略,I repeatedly done修饰dream.所以最后可翻译成正确的是Become your enemy is only a dream I repeatedly done.
还可以这样翻译:
Being your enemy is only a dream I repeatedly done.这样比较流畅.
或者用形式主语翻译:
It`s only a dream I repeatedly done that I become your enemy.