Hi. I had the stent deal when I was 42 so I can relate to your concerns. Before I go on, remember that every person is a unique case. Unfortunately in mine, the stent wasn't enough and I had to have a single bypass. I was very freaked about it (and everyone in the hospital was asking why I was in there at my age). In my case I had a clot that no one could explain since my heart was healthy in every other way.
I am sure you know that you have to go to your doctor and tell him about the continuing pain. It doesn't necessarily mean you need a bypass... but you do need to find out.
By the way, after my bypass everything was shiny. I had no more problems and it has been 12 years now.
God luck and be strong.
There could be more blockages that are too small to stent. In my case, some of my angina is actually spasms. I do have an artery that is 50% - 60% blocked and I will have to have bypass with that one. I want to hold off on that as long as I can. Are you taking a nitrate? There are some good ones. Isosorbide is one that is long lasting. I take that, but also keep NitroQuick with me to use.