Fell off now I will get back on

I have done nothing but eat bad for about a week now. I don't know how I expect the weight to come off if I keep eating like this & not exercising. Today I had a plan I packed my breakfast & lunch for work, however once I got here I did not want it. Instead I got Subway for lunch which was not so bad. I got a turkey on a roll up, but I also got chips & a Twix. Not so good. I am going to the gym tonight.
I think my problem is once I eat something bad ( such as candy & cookies) I just can not stop, & this goes on for days. I am going to stay away from cookies/candy & try to eat a lot of fruits & vegetables for a week & see if that helps. I am also going to go to the gym everyday this week.