Eating healthy

So I am on a journey to figure out how to eat better. I am a fast food junkie and believe that nothing is wrong with it. I also loves sweets and have no control. However, I am realizing that my 41 year old body is not metabolizing these bad food choices anymore and I need to change my habits. I am working with a nutritionist and trying to make a lifestyle change. For the most part I have been doing well with getting the good stuff in, more veggies and fruits, and taking some of the bad stuff away, however last night I broke down and got myself some mcdees (god i love them), all i got was a plain hamburger and small fries. 

They tasted GREAT. I did not feel sick after, I did feel a bit incomplete like I needed more food, but for the most part there was no feeling that made me feel like I should stay away (which I was hoping for). However, this am I am a raving cranky bitch. Granted today was a NO exercise day, but I wonder could bad food REALLY affect your mood ? 

When I was young I drank soda. I finally realized soda made me fell full and the enjoyment was not worth it. I quit soda.

I use to order the Grand French Toast at this wonderful bfast place, it was pure heaven, however I would feel like crap an hour after and be starving after a huge plate of french toast. Again I made the connection and the enjoyment was not worth it.

The big question I have for myself is will this happen with fast food or not for me.