three dots and a blah

I have been writing a lot lately but most of it has been my (book?)... (there they are) and my net class.
I have not been very happy with the net class.  I took the class to learn something.  I was hoping that I would get some constructive criticism and just maybe learn how to improve my writing.  The only criticism I have received is about my punctuation. The criticism is, "there are some problems you need to fix."  OK, what are they?  I was hoping the instructor would at least say what is wrong and maybe give me a lead  as to where to go for some help.  I was not given any help.  Unfortunately I know I do not have the greatest knowledge of punctuation and could use some help.  The class I am taking is not the place to go for help.
However, I have discovered  that using three dots (...) is not good.  My problem is that I have fallen in love with the three dots.  They solve a ton of problems for me.  "Word" allows me to use them without screaming at me with red or green lines so I assumed I had found my panacea for writing.
However,  my instructor told me to get rid of the dots (...).  It made me want to cry because it is sort of like having to return a wallet full of money that you just found.  You know you cannot keep it but it sure would be Nice to have the money.
Alas, poor me...adios my old friends...I will never forget you...If I ever become a famous writer I will resurrect you...