Feeling guitly

I am 8 wks and 3 days and I have been trying to get up and go for a walk even if it's for 15 min. As glow reminds me "let's go for a walk". I literally went for a 10 min. And was to tired to continue. Anyone else feeling this low on energy? I loooooove walking it's my thing but I can't seem to get the energy to get up go and do it, I'm feeling so guitly because I know it's good for both baby and I.