Jolly ranchers helped me a ton while I was pregnant with #2 and this baby. Only the green apple though. Occasionally the blue raspberry. I think it was just having something sour to suck on.
As for the exhaustion, rest when you can. Naps, getting to bed earlier, sleeping a little later. Any little bit will help. Also making sure that youre keeping up on eating every few hours (which may help the nausea as well). As counterproductive as it may sound, sometimes I find that taking a quick brisk walk will sometimes wake me up a bit.
It doesnt last forever. Now that Im getting closer to the second trimester Im starting to get some of my energy back. But Im still napping once a day most days, going to bed early, sleeping in a few minutes later, and just generally taking it easy. I get wiped out really quickly when I am "productive", Saturday I deep cleaned my kitchen and scrubbed my kitchen and dining room floors and I was done for the day. Literally had no energy for anything else.