Okay, just normal over the counter stuff. It won't work immediately, but COULD clear it up within a week or less.
For a normal cure, get several bags of vitamin C drops. The type which is 100% of vitamin C per day. Take about 5 to 12 a day. You might get diarrhetic, just so you know, but it WILL bolster up you immune system big time.
If that's not enough, there's Echinea (sp?) which ALSO bolsters up your system pretty strongly. DO NOT take this for more than a month however. It is STRONGER than Vitamin C overall.
Unsubstantiated in my experience (I haven't noticed much of a difference the one time I tried it) is also Zinc Tablets. I don't have much experience with these so I couldn't tell you.
For relief whilst you are going through it and waiting for things to clear up, try Nyquil at night, but definately try Dayquil for the daytime. It doesn't do a dang thing to cure it, but it does help clear things up greatly.
Also if it's a nasal cold or item of that arena, DO NOT ever suck it in, always bring tissues and blow ANYTHING out into a tissue. By not doing this, you could cause a nasal passage to get bacteria and get infected hence making the problem worse. You could also cause a backlog into your throat causing the bacteria to migrate downwards. Of course if they already have done this and it's too late, you could also try a saltwater OR soapwater rinse.
Basically, you suck it up the nose (be sure not to leave your throat open as it could cause choking) and either blow it out the nose, or spit it out the mouth...kind of gross and sick, but for those with post nasal drip it could be effective. For a soap water rinse you'd rinse with clean water, then a VERY MILD and low amount of soapy water (like a drop for 100-250 milliliters), and then clean water again.
Just some things that won't cure it immediately, but might aid in curing it faster.
Or of course you could spring for a doctor and go see them. If it's a virus they could give you penicillin, if it's a bacteria, well, they could give you over the counter stuff to relieve the symptoms, but otherwise will probably tell you to wait it out. The above are mostly herbal remedies and probably not approved by most doctors unless they are natural/herbal doctors.