Don't apologise so much. I've caused some problems for you too.
そんなに so much/that much
謝らないで don't apologise
私も I too
貴方に for you
迷惑かける cause some problems/cause some issues
「レッスン中に何度も先生は謝っています」というのは My teacher has been apologising over and over again during the lesson で表現できます。
参考になれば幸いです。