Do not think it is necessary to include reference letter into mailed application package. Put reference upon request on the resume should be ok.
BTW, be patient, job hunting is a hard work.


That's exactly what you should do. - "Reference is available upon request."
Attaching recomm letters may help a bit, but don't count on it. They always look for relevancy of your prior experience. Or if you can find someone who can connect you to the company, your odds are much improved.