Assuming the part in quotes is what you mean by "above two sentences", I have to say that this is only one sentence. (There is only one period at the end.)
To make it two sentences, you would have:
"I haven't had a day off since last Tuesday. I won't have any till Wednesday."
Either as one or as two sentences, the idea is completely understandable. To shorten it may require telling the facts of the sentence in a different way.
You could say, for example, "From last Wednesday through this coming Tuesday are all work days for me." However, I don't see it as any great improvement over what you already have!