Getting a cold once you no longer live at home isn't like getting a cold when your parents are there to take care of you. Sure you can call them and talk to them and get advice, but ultimately it's up to you what you do. There are little things I've learned as someone who seems to get sick and Google "ways to fight a cold" every other week, and I'd love to share them with you.
First things first, change your toothbrush and your sheets and pillowcases as soon as you are getting or get better. This ends up being more preventative of future illnesses instead of immediate relief, but still, it is important. Even if you don't necessarily see the benefits immediately, there's something nice about a fresh, clean set of sheets and then the feeling of a new toothbrush is amazing, and you just feel cleaner.
Along with changing your sheets and toothbrush, taking a hot bath is perfect. I tend to use salts to sooth my muscles, and lightly scented bath foams. Sweating out the toxins helps your body heal, and certain scents (and the steam) can help clear your sinuses.
If you prefer to shower, I suggest taking a hot shower to let the steam clear your sinuses. Then, taking a cough drop or two and putting them near the drain of the shower while you stand in the steam. My favorite cough drops are eucalyptus – I see the most success when I use them – and they are perfect for a nice long steam. Your sinuses will thank you, trust me.
If you see major success with eucalyptus, I suggest melting some in some hot water over the stove and letting the steam release the scent. (Essential oils work better but I realize not everyone wants to buy them.) It's a subtle method, but then it also doubles as a slight humidifier.
It's hard to convince yourself to go out and buy things you won't constantly use like humidifiers or a specific essential oil to dissolve in the shower to clear your sinuses, so I think using just cough drops is a perfect hack. But, if you do got the essential oils route, spray some on your freshly cleaned sheets to keep your sinuses clear and your body feeling as good as possible.
Regardless, sleep and water are the best methods to let your body heal. Sure medicine helps and cleared sinuses feel good, but actual letting your body heal is the most important. Rest up, and drink some water and just let yourself relax...sometimes that's what you really need.