Is there an idiomatic way to express being overwhelmed by vocabulary? The other day, I wanted to describe my shock regarding the overwhelming HSK6 vocabulary list (~2500 additional words) to my teacher, so I came up with a self-made idiom 词山词海: taking 人山人海 and replacing 人 with 词.  I thought it was apt and quite proud of my creation, by my teacher disagreed.
I can't think of an idiomatic way to express this sense of being overwhelmed by vocabulary when learning a language in Chinese.  Sure, I could say 词汇太多了, but it doesn't have the sense of being overwhelmed.
Question: Is there an idiomatic way to express being overwhelmed by vocabulary?
无从说起：
指事情太繁杂，要说的话很多，但不知道该从哪里说起。
Things are too complicated and there are many things to say, but don’t know where to start.
一言难尽：形容事情曲折复杂，不是一句话能说清楚的。
Describe things tortuous and complex, a sentence cannot make it clear.