strong pulse...is it pph?

Hello- I Hope someone can help me because this has been going on for 2 yrs, & I have'nt gotten any answers. For the last 3 yrs or so I have noticed I am getting more & more out of breath while resting,It comes & goes-really bad after I eat-also,fatigue is getting worse-sometimes I wake up after 7 hrs of sleep exhausted.My heart  beats through my chest constantly-all the time.Worse after a meal or exertion.I have been a heavy smoker for 20 yrs.The bounding pulse is very scary.It is constant-when I look down, you can see my pulse through my shirt.I asked my Dr about it & he said it was normal-ordered a pft(at my request)and came back 61% diffusion,everything else normal.Holter monitor for 24 hrs was normal-2 echoes-normal,and 3 normal ekg's. Please don't say anxiety-I tried xanax and it did'nt help at all.(gave it a good shot-4 yrs of it) I wonder if it is pulmonary hypertension-I did take phentermine in my 20's and ephedrine(mini-thins),also in my 20's to keep my weight down-I thought for sure that the xanax would help-but I would still get out of breath and you could still see my heart pounding.I have read about pph and it sounds like it to me.