Been taking (2) phentermine per day, over the past 2 weeks it no longer works. feeling very bloated, what should i do?

That is very: common with phentermine. The truth is that you will simply have to stop eating more calories than you utilize in a 24 hour period. That is the only effective way to lose weight. There is no magic to the simple math of burn more calories than you take in. There are a variety of ways to do this and at your age you should be capable.