I'm 21, I started phen a week ago from today, therefore having taken it for 7 days. 1 pill an hour before I eat. Last night scared me. I've had the rapid heart beat off and on but was going to give it a week for my body to get used to before calling the doctor. Well last night I was up till 5 am with a really strong pounding heart beat for a few hours. I also feel like I can't catch my breath and have to take a deep breath often and can't catch it sometimes. Some sharp chest pains too. Here it is over 24 hrs after taking my last pill, and my chest still hurts. My throat kinda feels weird like something pushing on it. I haven't been eating much AT ALL. Maybe me not eating much is making my 1 pill seem like an overdose to my body..I called the doctors office and they said to stop taking it but I didnt tell them I wasn't eating much at all. For instance yesterday I had tomato, lettuce and pickle on bread. and a granola bar. Thats it. I did 30 minutes on the treadmill and literally felt 60 yrs old and couldnt catch my breath. Im too scared to take it today. My doctor is on vacation and the earliest I can see her is 6 days away ugh...I was thinking eat good today and dont take it. Tomorrow take half and see what happens. I'm so depressed now!! UGH! Oh and I also noticed pplo were talking about hair loss!? That TERRIFIES me because ever since I had my baby 15 months ago, I've been losing hair and its thinned so much. I expected it for a couple months after pregnancy but 15 months after!? It makes me want to cry as I used to have enough hair for 3 people. IF phentermine causes hair loss, I cannot continue anway as I'm losing hair without it...I'm so depressed. I'm only 21 like seriously..What should I do, and if I should stop phen, whats the next best alternative. The heart and chest and breathing are scary..