You're only a few weeks out! At that point I couldn't eat more than a few spoonfuls of anything. Journal EVERYTHING. When you're hitting your totals for protein\carbs\fat\calories there doesn't have to be any guilt over what you're eating. If you're not hitting your totals, then you need to adjust. It will take some time before you can get adequate calories. Talk to your Nut or team about what their recommendation is for you at each stage and when you should be advancing your diet.

When your very low carb low cal and need sodium my dr told me drink a sports drink. I would vitamin water zero or poweraide zero just one a day. It really helped I was also told if I felt I needed salt (leg. Cramps are a good sign) put a teaspoon of light salt in a cup and drink. I had to do this the first month or so

I was told an empty sleeve is an unhappy sleeve, so I needed to eat every couple of hours for awhile. Since I couldn't get but a few tablespoons in at a time this worked really well for me. As for sodium, I have water retention issues so they recommended potassium pills for me. Really helped with the leg cramps. Wanting to eat a lot in the evenings might be more a habit from your presurgery life than actual hunger. try something small but really high in protein and water to avoid overdoing it late in the evening.

This is just the beginning, so be patient with yourself and keep sipping and walking. You will be fine.