I try to swim as much as I can, but you're right, it's hard when you're so tired. I think the cold water helps to wake you up, too.
Good luck!
Haha omg story of our life now I think :P I often find myself napping so much now instead of getting out and enjoying a walk. However I guess we just gotta do the best we can.. cuz rest is needed too right? We shouldn't feel guilty for taking that extra hour a day to nap :P we are growing little humans after all!
I'm fortunate cuz I work on a farm so I really am always quite active. Lots of walking and physical work. However I do like to try to get out for a stroll. Good for the mind. Give it a try, the outdoors does something different to your moods and energy, with the fresh air, than a treadmill might. Try to force yourself to even take a short walk and perhaps you'll find yourself going for a jog, and maybe the outdoors will wake you up. Then if u are still really tired at least you can rest easy knowing you tried ;)
I'm only 15 weeks so.. I have no shame resting a lot. Our bodies are enduring enough as it is :)