How can I get better results out of my exercise routine?

Okay, forgive me if I sound like a novice but I haven't been doing this for a while. I'm 22yrs old and 5'5". I've been doing a five days on one day off routine. I get up in the morning, eat a bowl of cheerios and an apple. I then proceed to use the ab slide doing eight sets of 10. I follow that will some free weights and some crunches, etc. Then I hit the treadmill for at least a mile. After that I eat a salad consisting of gs. lettuce, chicken with a dressing that consists of honey, Dijon mustard, lemon, lemon juice and lemon zest, and olive oil. For a snack if I'm hungry during the rest of the day, I eat an ortment of raisins, cranberries, walnuts, pecans, almonds. On May 15th I weighed 178 pounds. I'm down to 155 however I didn't start working out until at least the end of may. I think most of it was from college drinking but nonetheless, I'd like to lose five more pounds then stop. Okay, the question is how I get past the wall I've hit? I'm not losing or gaining weight anymore. I figured the mile a day would help which I started five days ago. I know results take time but I was wondering if anyone with a little more experience could shed some light on this.