I'm so sorry that you're feeling horrible! It's definitely hard during that 1st trimester when you're nauseous and having to take care of another child. I experienced that while pregnant with my third and having a 4 1/2 and 2 1/2 year old at home! UGH! Even though the thought of eating made me feel ill, I still tried to eat several little meals thru-out the day that included a lot of carbs - toast, crackers, pasta, cereal without the milk. Ginger Ale also seemed to help settle my stomach. I'm not much of a Ginger fan, but there are a lot of things to try, including candied ginger, ginger lollipops, and raw ginger. You might have to go to a health food store for these things, but it's supposed to be great for morning sickness!
As far as the cold, there are healthy alternatives you can try, but not many. Humidifiers are great to use around the clock in the house. Flushing your sinuses out with saline will help head congestion. Again, a health food store will carry a Netti (I can't remember how to spell it?) Pot - it looks like a small tea pot that you fill with saline. You tip your head to the side over the sink and put the spout in one of your nostrils and pour the solution in. It feels a little weird going thru your sinus cavities and draining out your other nostril, but it can help immenseley! If you can't find one, you can try doing the same thing with just a bottle of saline that you can find in the cold medicine section of any grocery store. If you have a cough, you can try swallowing a tablespoon of honey. It's supposed to help coat your throat and reduce coughing, and you can take it more often than regular cough medicine. If your throat hurts, try gargling with the warmest temp. salt water you can. Mix approx. a 1/2 teasp. of salt with a half cup of water. Again, you can do this as many times as needed. The best thing to do is rest!! I know that's hard to do with a little one, but lay down when she does and take the opportunity to do so when your husband is home (that's wonderful he's being so helpful!). There are over the counter medications they say you can take while pregnant, if all else fails - talk to the pharmacist at the store. Don't feel guilty if you have to use those!!
I hope that maybe something in this message will be helpful to you!! Good luck with everything!