There seems to be a lot of emotional undercurrent going on with your wife (and you, but you know about that
). A lot of people keep things inside for years for many different reasons, sometimes they feel if they just push it all down it will go away and they don't want to deal with it, sometimes it's fear, sometimes it's that their feelings go against the life they think they should have-- it's endless really. And the only way you're going to know what's really going on with your wife and why it's been kept inside so long is to ask her.
So... counseling sounds like exactly what the two of you need right now. I'm glad you found somebody who is knowledgeable about these types of relationships, that makes a big difference.
Something I've learned (in my schooling to become a counselor, but also in my private life as well) is that there is an interesting process that happens with love and relationships that is just as much physiological as mental and emotional. Around here it's called NRE, but basically when you are attracted to somebody your body releases a ton of chemicals -- seratonin and dopamine-- which make you feel GOOD beyond belief. The purpose of these chemicals is to bond you with a mate and keep you there, at least long enough to procreate and have a baby (the chemicals generally taper off after about 18 months), and then usually other chemicals are released (oxytocin) which keep you bonded after that.
The reason the chemicals dissipate after 18 months or so is that they are so powerful that you wouldn't be able to function properly in life if they stayed forever! But the downside is that these chemicals-- which activate the same part of the brain as drugs like heroin-- can also affect your judgment and impulse control. So basically you see the person you're into through seratonin-tinted glasses. Their faults are not noticed or are no big deal, their positives accentuated, etc.
And when the drugs wear off, that's when you really see if what you have is a strong bond, or not. This point-- is where love actually happens. When you start to see the person as they REALLY are, and choose to love them. It's also where the work comes in, with needing to communicate about issues and work through them.
People can make really bad decisions in the midst of this NRE stage which is why around here they say wait at LEAST a year or maybe more before making big decisions like moving across country, moving in, etc. Another side effect is that their focus can be so on the person that they're having these feelings for that they literally ignore the other people or responsibilities in their lives. And lastly, people can get addicted to that "feeling", and start flitting here and there to get that rush and high.
So maybe a question you might want to ask in counseling would be if she could see waiting, say six months, and allowing the two of you to work through things in counseling, to build your foundations, to work on yourselves independently so that you can bring your best self to the relationship. I would think that's not a lot of time for her to be on "pause", but enough time to really take a good deep breath, clear the air of the NRE, come down to earth and take care of each other for a little bit. It might also give you some time to look at where your insecurities are coming from and work through them in counseling where you can have help in expressing those concerns and seeing what is something you need to work on for yourself and what might be concerns that you can work on with your partner (i.e. need more hugs and reassurances when she's in the throes of NRE, or something like that).
The concern in the back of my head is that she may be becoming addicted to that NRE feeling, the seratonin and dopamine high (i.e. she wants to do swinging where she feels that high and runs with it until she doesn't and then finds somebody else who provides it, with no feelings or actual relationships getting in the way.) And chasing that high could definitely impact your relationship (and her own life) if not done with care, caution and consideration. This, of course, is just a possibility, but something that could be discussed more deeply with a professional.