"There are many great English writings of which I am unaware of" should have one less 'of' in there. I also believe it should be 'that' instead of 'which.'
After considering the sentences after the correction it's just a matter of "I am unaware of" and "I don't know."
They almost mean the same thing, but in this context, one can be aware of something and still not "know" the English writing. However, one cannot know about a piece of literature without being aware of it. That is, if one "knows" it, one is aware of it. However, if one is "aware" of it, one may not necessarily "know" it.
It is usual to find "aware" associated with "having heard of" and "know" associated with "understanding and comprehension" (
Consider the example:
Are you aware of the man in your backyard?
Do you know the man in your backyard?
In terms of semantics, they are very similar, but the latter implies a personal relationship or a deeper level of understanding or comprehension rather than simply "knowing the existence of"
I hope this helps!