Day one of Phentermine. Experiences?

I’ve gained probably 45 lbs within the last year or two and my weight keeps increasing even with diet changes so my doctor prescribed me 37.5 mg of phentermine. Took it for the first time this morning and now it’s 11pm and the only thing I’ve eaten today was a to go box of fries. It’s like I still feel the hunger pangs in my stomach but I don’t have the feeling of being hungry. Has anyone had a similar experience?