"Has anyone else ever experienced anything like this?" Yes, pretty much everyone on this message board. You need to read the archives and also start doing research on cervical dysplasia (the cause of abnormal Paps) so you can learn the facts.
Abnormal Pap smears are very common. Usually the dysplasia resolves on its own in a few months. If it progresses or does not resolve, very minor procedures are done to remove the cells (usually the LEEP procedure) to prevent them turning into cervical cancer. Dysplasia is pretty much 100% treatable. So, calm down
Your wife will be fine.
Most dysplasia (which is what causes abnormal Paps) is caused by HPV. Something like 70-90% of the adult population will be exposed to HPV at some point. IT IS EXTREMELY COMMON because it is EXTREMELY CONTAGIOUS. Also, it can stay dormant in the body for *decades,* so your wife could've acquired it many years ago or YOU could've acquired it years ago and given it to her.
As to how scared you should be? You shouldn't be scared. First of all, fear doesn't help any situation so it's not advisable to be scared
Secondly, nearly 100% of cervical dysplasia cases will either resolve spontaneously, or be successfully treated, so there's no reason to panic. Good luck!