What is a good, safe diet pill that works?

Since 2008 I've lost 150lbs. I am 5'7 and weigh about 145 lbs. My goal weight of 140 is stressing me out, I just can't drop these last 5 lbs! I eat healthy 95% of the time, and the other 5% isn't AWFUL stuff (nothing fried, nothing high in sugar) I'm just a big snacker so I try to pick on things like rice cakes and special k bars. I work out 2-3 times a week with a trainer. Someone recommended that I try a diet pill or metabolism booster to get over this hurdle, but I'm scared. I had a bad experience with Stacker 2 many years ago that always left me fearful to try diet pills... any sugguestions for something that actually works to help curb the appetite without making me jittery? Thanks!