Can panic attacks suddenly go away away & not return? i've had panic attacks for about a year, and haven't had one for almost 2 weeks. is this normal?

It's possible: Panic attacks are part of many psychiatric disorders; major depression, panic disorder, specific phobias and drug abuse etc. Once the disorder is treated the panic attacks will stop. Panic disorder has a course of periods without panic attacks even without treatment for years with chances of coming back. Enjoy the time without panic:).

Panic Attacks: It is unlikely but possible if the situation you feared no longer exists. Also if you learned to percieve more accurately panic attacks usually subside. Anxiety and panic is driven by mispercieing situations and interactions. If you perceive more accurately you may have significantly reduced there occurence. Best wishes.

Panic: Yes it is possible with good coping skills. Good job.