What's the difference between Phentermine 37.5 and PhenObestin 37.5 ?

They say is the same thing, but I was just wondering.. I'm 41, 5-2, 159lbs. My goal is to go down to 135lbs by February 25, 2012 is a special date for me... Months ago, I started taking Phentermine 37.5 daily and b6/b12 shot once a week.. I started shaking, dizziness, heart rate zillion miles per hr, so I stopped everything... Although i lost 15lbs on this.. But my health comes first.. I am so determined to lose weight I want to go back on the phemtermine and b12 pills instead of shot. I looked it up online and people say that phentermine 37.5mg is now called PhenObestin 37.5mg... Is there a difference? I really want to lose 24lbs by Feb. 25th. I don't exercise I don't have the time. I'm lucky if I get to sit for 10 mins.  Can anyone help??

My Weight now: 159lbs
My Goal is: 135lbs.
Need to Lose 24