Out of the Blue Hypertension?

Last Thursday, I experienced an sudden episode of nausea, elevated blood pressure, dizziness, rapid heart rate, and diarrhea. I thought I was going to die, but that ped, the diarrhea went away the only thing that remained was the elevated blood pressure and the feeling that there is pressure in my head. Its not a headache nor do I feel pain it just feels like there is something pushing out of head.I went to my doctor on a follow up to a past visit for an unrelated worry. She said that I had mild hypertension according to the bp reading of 147/75 that day and told me to go on a diet that is low in salt, fat and high in fruits and veggies, and to include cardio exercise. I have never had high blood pressure, I have always lifted weights, and just two weeks ago I checked my blood pressure and it was 122/81 and now it has been anywhere between 138/72- 159/79 for the past 4 days. I feel as if this is not something that my diet and lifestyle has created, for god sakes I'm only 20 and not overweight and no caffeine, but I feel that something else has triggered this out of the blue hypertension. Have anyone had any experienced with this, should I go to the cardiologist. Why would sudden hypertension occur in another wise healthy young male? And no I was not stressed or emotionally distraught prior to this episode, but now I am starting to get depressed over the fact that I don't know whats going on with me and now I feel like crap.