I have a nice steamy hot shower just before i crawl into bed and it seems to help my congestion under control enough to get some sleep.
I've had congestion since before my positive test during week 4 - apparently it's a common symptom. A few weeks ago I had a pretty severe head cold like you describe (thanks, sick co-worker!). I had to use two pillows too and didn't sleep well for several days. I just ate a lot of cough drops and drank lots of fluids, got extra sleep. A humidifier might help if you have one. Feel better.