Hi Deb,
I had all-day nausea (thankfully no vomiting or constipation) with my first pregnancy for the first 5 mos and for 7 mos with my second pregnancy. It helped to always keep a little something in my stomach all the time, so I nibbled on saltines before getting out of bed and saltines and crystallized ginger throughout the day. Ginger helps the stomach empty faster, which is how it relieves nausea. Sucking on fresh lemons also helped. Be careful not to eat too much, though, because you don't want to gain too much weight (like I did!).
Keep up with a high fiber diet to reduce constipation: lots of fruits, vegies, and nuts. These provide excellent nutrition along with the fiber. You can also eat things like chia seeds and shiratake noodles, which are very high in fiber. For chia seeds, it's best to soak them in some kind of liquid for 1/2 hour or so before eating, as they swell. You can actually make a very lovely no-cooking-required pudding out of them that's similar to tapioca: soak 3/4 cup seeds in 2 cups milk-product of your choice (cow, goat, soy, almond, rice, hemp, etc., but keep away from raw, unpasteurized milks because of the risk of listeriosis) or juice for 1/2 hour, stir frequently to prevent clumping. Add in a little vanilla, flavorings of your choice and/or fruit and you have a really satisfying low-calorie, high fiber healthy snack. Chia is loaded with omega-3 fatty acids, so it's also great for cardiovascular and neurological health for you and baby.
The other thing that really helped me with the nausea was not to keep anything tight around my waist, so I wore dresses only -- no pants or skirts. The nausea was also better if I got plenty of rest and a good 9 - 10 hours sleep each night. Remember -- you're growing a new person, and that takes a lot of energy!
I hope you're feeling better soon. Just keep thinking of the "prize" at the end of the process!