I agree with the morning sickness and general exhaustion being some of the worst parts of the first trimester! Some days, I just wanted to curl up and sleep it off, but work and life kept me going throughout that phase. It was definitely a challenge, and thankfully, things started looking up after week 14 or so, when the sickness eventually subsided.
As for the later trimesters, the physical demands increase, and moving around becomes a little harder with the growing bump, but by then, you're more emotionally stable and energy levels are generally up, which helps compensate for the physical struggles.