Having a Good Mindset

Hey guys,
My whole life, I've been a little heavier than I was comfortable with. I was never terribly overweight, but I definitely had some self esteem issues related to my weight and how I looked. This past December, I finally got the determination to make a change. I have lost about 40 pounds, since my heaviest was around 170. My biggest concern right now is how I'm thinking about continuing with my current lifestyle. Some days I can have a treat or eat a not perfectly clean meal and it'll be okay. Other days, I have an overwhelming amount of guilt and anxiety for eating something that is completely "safe". Because of my self esteem issues, I'm worried that I could be switching to a mindset that is closer to someone suffering from an eating disorder. I weigh myself every day, and I get super excited when I lose another pound. Even when I know that I'm gaining muscle, I get disappointed seeing myself gain a pound. Where do you draw the line between being determined to be healthy and determined to lose weight? Sorry if that isn't very clear!
-Haley Zahn