Your advice would be greatly appreciated.
As you state, all MArch programs not only require a portfolio but many also require a freehand drawing course prior to admission. The course, a life or figure drawing course, can be taken at an area community college if desired. It is an opportunity to develop your drawing skills but also possibly obtain a letter of recommendation from the instructor.
In addition, begin to draw every day. Purchase a sketchbook and draw everyday objects -- shoe, chair, etc. Do not worry about quality but focus on developing your ability to see. In addition, begin to become aware of your built environment.
You could also consider attending a summer program -- http://archcareers.org/
If you are near an architecture program visit to talk with students even if you do not wish to attend. Attend their lecture series, etc.