You can get a cough suppressant at Wal-Mart for 2.14 USD. That'll calm your urge to cough, and it will thicken your mucous and give you some relief.
Take plain old Benadryl to slow the runny nose, in its generic form. It's dirt cheap, too. Most new over-the-counter anti-histamines aren't effective in your situation...they just don't work well enough.
Take a shot or two of Brandy, or any alcohol, to calm your cough (it's the effective part in most prescribed cough medicines), and it'll also help with the congestion, and make you more relaxed.
Drink plenty of water, and simple carbs, like candy (suck on hard candy), or juice, so that your body has energy. Eat some protein when your appetite permits.
If your phlegm is green, or white, your body is doing its thing, and you'll likely be o.k. Unless it's really gross, you probably don't have an infection, but, rather, it's your body worked against histamines. (Making you better, and dealing with the virus.)
If your phlegm is red, and your nose isn't all dried out, or if your cough is really, really, really bad, you could have pneumonia, which could require a medical professional. If you're wheezing real bad...get to a doctor, right away. If you have pneumonia you need to cough, and keep coughing, and likely get some corticosteroid from a doctor for lung inflammation. You probably do not have pneumonia, but, if you are real sick, it could be.
There's been a real bad cold going around this year, and most folks I know have had it, me included. If you have it, it'll pass in about two weeks.
You might enjoy a warm liquid like hot chicken soup, or hot brandy. It'll help your sinuses clear.
Also, a warm, steamy, shower, will help your head drain, and you can get saline solution on the cheap to wash your sinuses out, too.
Avoid to much Tylenol (it's hepa-toxic), and stay away from decongestants because they are vaso-constrictors, and can run your blood pressure sky high.
A cold generally doesn't give you much of a fever. The flu will give you a temp, and you will feel REALLY bad.
I had the flu, back in July, and it sucked, real bad. It took a good three weeks to get itself straightened out.
Either way, you end up treating the symptoms, and, in most cases, simple remedies work about as well as the expensive ones, unless you require hospitalization.
I've had my doctor friends complain about "sniffly, sneezies" what a pain they are for their practice. LOL
Get well soon.