I did not like the structure of this essay, as it really 
does not have much of one. 

The first paragraph does not tell you where this essay is headed. 
Some paragraphs (such as paragraph 2) talks about multiple things 
(such as topics in CS and 
my personal feelings about one particular CS topic).  

Pargraphs and sentences do not flow together.
Discussion of CS Theory in paragraph 2 
is interrupted by CS hardware in paragraph 3 before resuming in paragraph 4. 

Without structure, the reader has no idea what the next sentence will
be about; sudden jumps of thought occur (such as in the last
paragraph, jumping to "CS is a science" and then to I am a CS person.
Even in paragraph 1, the "I Believe" sentence is not connected to the 
previous sentence.

Each sentence does make senese individually, though.