I agree with PP, all totally normal.
Currently a few weeks out from the end of my first trimester with second and in the throes of this now as well. It was the same with my first.
i just try to eat as well as possible when I do feel okay, and then if nausea hits and I get a hunger on then I allow myself to eat whatever will get me through.
My days are generally breakfast around 7am, elevensies or lunch at 11:30/45 if I can’t make it, then second lunch or big snack around 15:00 (😅) then make a bit extra for myself when making DS’s dinner and have something with him. Then, dinner with DH after DS has gone to bed. Plus snacks hahaha.
You do feel as if you are constantly eating but there’s a lot going on which you need energy for. And don’t worry too much about not exercising, you may find you regain the energy for this in the second trimester.
Just listen to your body, if it wants rest, then rest. If it wants to eat, then eat. Once the placenta is formed, the baby literally only takes the nutrients it needs so this can also help you feel a little bit better if you eat something a bit rubbish every once in a while.