I am 30 and weight 155, and I am 5'5 tall. I want to be able to fit into a nice size 8 with out anything hanging over the edges.

what should I do to help myself get there?
I am thinking goal weight will be 130. so I have 20 pounds to lose. It is really going to be hard. I have already taken off 20 pounds and now I am stuck in a platue. I cant say I did the 1st 20 pounds that right way. I did a lot of the starving myself and working out like crazy. I was always doing the treadmill. i would do 3 miles everytime i got on it. Now when I get on the treadmill after about a mile I am ready to get off of it. I also took some Diet pills Lipo 6. they helped give me the energy that I was not getting from food. Even though I did it the wrong way the weight is staying off but i think it is because i am staying active.
I have a treadmill at home and an exercise machine...
please help me i need all the advice i can get. i need some motivation and suport as well.
Amanda