What causes stomach/acid indegestion if I never have had it but now I've got it twice lately and it HURTS BAD?

About 6 months ago, i started having chest and throat pains that were severe.. something I never felt before. I thought I was bad sick so I went to the dr and they did all kind of tests and determined it was acid indegestion and gave me aciphex and after a few days it was gone. I dont have those anymore, and last week I started getting a similar pain, but lower on my chest almost in my stomach. It hurt so bad I started thinking I had tweaked my back because the pain was so bad it hurt my back too. I started thinking and thought ok maybe this was the indegestion again even tho the pain was in a diff place kinda (lower down my chest) but it worked. I took some over the counter acid ind. & sour stomach pills and it helped. So what can cause this out of the blue?! I'm 25 male, and its only happened twice to me.. but im afraid it will happen again. Do I need to change my diet or soemthing?!