I'm not sure if any of you have ever had guilt when you eat certain foods. Today, I went to Big Boy's (a diner-type restaurant) and had an amazing Garlic mushroom Swiss burger with fries. Keep in mind, I only ate half of the burger, half of the fries, and had only water to drink. I ate about 1 pm, and I'm still full.
Usually, I eat home-cooked meals, so this may just be something I'm uncomfortable with.
I feel as though I'm guilty of eating what I ate for lunch. I don't know if it was because it was supremely delicious, or because I just shouldn't have had both foods. I've already lost 3 lb. (in 5 days)

and I really am not looking forward to gaining. I've been exercising every day for an hour (different routines every day) as well, which does help me feel better about myself.
I've cut my portions in half whenever I eat, unless it's small enough to where I can consider it OK to eat the whole portion.
Have any of you ever had guilt like this? Maybe it's just because I'm still full, but I really don't know how to deal with this.
I think some of my guilt is coming from looking at the My FitnessPal app where it shows the chart of fats, proteins, carbs etc. Most of what I ate today was fat/carbs. That kind of worries me.
So, any help over here? Thanks in advance, also!