You can do a double Major BA in Communications at Mac. You can do a double major and minor if your really want.
As Sarah said, you will need to email the professors explaining your situation to get into the classes they teach. That way you will essentially be shadowing in the program and if your marks are high enough you will be admitted into the program at the end of 2nd year. Just don't send an email demanding to get in--explain that you had a tough transition to university etc, and you will definitely work on improving your grades in second year.
The professors in Communications are pretty good. I'd suggest you ask Dr. Savage (
[email protected]) if you can get a waiver into the Research Methods courses (2A03, 2B03). I'll post a list of the courses offered in Communications. The master timetable on the Registrar's site has the list along with the Professors who teach them:
http://registrar.mcmaster.ca /CALEN...12/pg1855.html
If you need any extra help you should go to the Academic Advisers for Humanities in CNH. Feel free to message me about courses and the Communications program.