Lol i had to learn the hard way, so heres my advuce to feel as best you can and avoid frustrations...
Nap. Let the housework slide. Get hubby to cook or go to inlaws for free meals that you wont have to clean up after. Junk foods and sugary drinks (whilst satisfying a craving and are yummy) zap your energy so enjoy fresh juices & smoothies, salads, fruit salad etc to give you energy. pasta and bread-based meals are good for a boost but are also heavy meals so wait patiently for the second wind of energy you might get from them. So whilst youre waiting, nap some more! Don't expect your day to be full or productive. If you can stay awake for a film, you're doing well! Don't stress if stuff doesn't get done straight away. Set your time limits to a week, not 'today' or 'tomorrow' tasks :)
Completely normal to feel fatigue in your 3rd trimester. The only suggestion is to nap when you can. Even a half hour nap can make a huge difference. I have a toddler and I have 62 days left. If he naps I lay down and relax or nap also. My laundry can wait. Get sleep while you can because once your baby comes you will feel a whole other knd of tired caring for two young ones!