We went through the same problem with our daughter, who is now 10 months (today). It stinks that there is nothing you can give a baby...however, when she was diagnosed with a sinus infection, she did get Amoxicillin. It worked wonders.
What to do. Turn on a humidifier in his room. We have a warm air mist one (Vicks) that we love, and some days it runs all day long to keep her room humid. Do your research about the pros and cons on warm vs. cold air humidifiers to see which you prefer.
Eleveate his mattress. You have a couple of options. You can buy the wedge at Babies R Us and put it under one side of his mattress; you can elevate it with a rolled up blanket; or you can do what we did and stick some books under the legs on on side of her crib. The elevation helps with drainage, and really helped our daughter.
I'm not sure if your doctor mentioned this, but sometimes a cold can lead to an ear infection. We, unfortunately found this out the hard way. Tell, tell signs for us...baby did not want to lay down and fought to stay upright and her appetite changed. (Our daughter never ran a fever.)
As for the aspirator, I found that using the Little Noses saline spray with the aspirator made it more effective. I still haven't found a way to make it easier to use. My mom can cradle her in her arm and use the other hand to work the aspirator and it seems less invasive. I'm not that good.
I'm not sure I'm the right person to give advice about sleeping. We didn't try to get our daughter on a schedule until four months and we used Dr. Ferber's book to help us establish one. If we got seven to eight hours straight from month 3 to 7, we were happy. We finally started putting her to bed later so the 4 a.m. (we had it, too) waking became a 6 a.m. or 7 a.m. waking. She now goes down at 7:30 p.m. and wakes at 7:30 a.m. with two naps (2 hrs in the morning and 1 hour in the afternoon).
I apologize if I was too wordy. I hope this helps. Good luck with the cold (I know they are not fun) and with your transition back to work.