Eh sayang, ni memang pregnancy fatigue lah, apatah lagi ni kandungan yang ke-4 so your body dah tau what's coming! A few of my mum friends said the same thing, energi habis tengah hari, then sudden waves of feeling sick especially when hidu bau masak-masak or strong smells, some of us found it helped to rest when the body says rest, jangan paksa sangat. But since ni pregnancy ke-4 and the pattern feels a bit different from your previous ones, better check with your gynae just to make sure everything's on track, ya, sometimes our body changes as we get older and pregnant more times. In the meantime, try to have lighter meals, stay hydrated, and pencil in nap time because honestly with three kids already, your body is working overtime!