i'm sorry for this difficult and painful experience you are having.
it is not, however, hopeless. by coming to this online community you have already taken an important first step toward proactively managing your situation and...getting much needed support.
the main point i would like to make is that timing is everything. your approach with your wife, therefore, must recognize the futility of "overselling" your marriage to someone who is in the sugar high phase of their affair. based on your post, it seems that your wife knows you have skin in the game and want to save your marriage. that's all she needs to know for now.
until now, her affair has enjoyed the free ride status of a secret relationship: it's all benefit and no cost. this has now changed and it will probably accelerate the end of the honeymoon phase of their affair. this is where your possibilites begin, but you must be very pateint and clever. i personally suggest not continuing to read her emails (think of your own stated desire to maintain dignity), but i do suggest paying attention to signs that her affair is weakening. possible signs: she will start spending more time with girlfriends, she will change her attitude toward you and may present herself as less self-assured. look at other posts and mwd's book "divorce remedy" for further clues.
until then, remember this. in her current state your wife will receive negative evidence about you - things that tend to justify her action of having the affair or doubting the marriage. she will tend to block positive information about your or your marriage, especially if it comes from you. what this means is that during this time you should avoid doing things that irritate your relationship with your wife, within the limits of dignity. later, you can begin carefully submitting positive evidence when she moves into the uncertainty phase of her affair - which almost always happens.
what does this look like? it means be civilized and kind, but self-protective. take care of yourself and go through the motions of doing the things that make you a dignified and valuable person (i use the expression "go through the motions" because this it what it will feel like, but the benefits will be very real). improve yourself. don't pursue. let me say that again: don't pursue. and if she resists going to counseling, drop it like a hot potatoe and go yourself.
think about this very carefully: if your spouse has to devote any energy to resisting your efforts to talk about, repair or counsel the relationship she will lean against you with everything she's got. if you totally withdraw from field, she has nothing to lean into and must then begin sorting through her own very strong mixed feelings which will increasingly develop if you are patient.
keep posting and if you see signs of uncertainty, get lots of input so you can make the most of the opportunity.
