L.M.
First of all it is normal for your belly to show earlier with each pregnancy. I have 3 children and it did show much earlier with my 2nd, a son. Luckily those big style shirts were in style and I was able to just get mediums and larges at Target and conceal it a bit longer. LOL But truthfully even with showing sooner, I didn't gain an over abundance of weight ~ only about 25 - 30 lbs. Especially if you are so active I wouldn't be that concerned about the weight gain or with what you are craving.
Secondly, a second baby is a HUGE change and you have every right, even if the baby was planned to be feeling the way you are. Your feelings are perfectly normal. With my third, my princess, I became pregnant sooner then I had wanted and I was stressing out and felt depressed for much of the pregnancy. My husband tried to be supportive and told me to stay positive, but it was hard. It was actually my mother-in-law who helped. She expressed her feelings when she was unexpectedly pregnant with my husband. He was also unplanned and she said she was depressed and worrying about all the changes till about the time she felt him moving and kicking alot and then for the most part she was at ease. It took me a bit longer to be able to let go of some of those feelings, but worrying about the future is common. Now I know my situation is a bit different being a not planned at the moment pregnancy, but the feelings were the same.
I just wanted to let you know your feelings are normal and hormonal. Congratulations also and if you need to talk just send me a message. I wouldn't be concerned unless your feelings worsen or linger after the birth of the baby.