I am in a similar situation although, rather than being discovered, I confessed all to my wife and after a rollercoaster ride of acceptance/non acceptance, she finally gave me the ultimatum to quit or it's over. I quit immediately and had a full and final purge.
However, as you have discovered, it's not that easy. My dysphoria comes and goes; I get the full range of emotions 'what on earth was I doing?' to wanting to transition. Given the wide variance of feelings, I know that transition is not appropriate for me but, recently, I've found fighting the urges to restock and dress increasingly hard to fight and, like you, I'm now seriously considering buying a few items in secret.
As I've written in other posts, I have a great deal of sympathy for wives who have this sprung on them after several years/decades of marriage and the thing that I never thought about was how my wife would feel about the deception. In many respects, this was a harder pill for her to swallow that coming to terms with the fact that her husband liked to wear high heels and a wig, not because of some sexual deviancy but because it stemmed from a nagging wish that he'd been born female.
Equally, I know that the current situation is not healthy for me, or indeed for you in your case. The problem is, as we've both discovered, the feelings don't go away and trying to surpress them leads to stress and anxiety with consequential damage to one's health and relationships. I would love to feel able to confront my wife and say that, whilst I love her, I can't continue as I am and negotiate a compromise; however I am terrified that this would reignite the issues, cause her a lot of upset as it did last time and, at worst, lead to the immediate & permanent breakdown of our relationship. I know that others will say that she should understand and be tolerant but the bottom line is that had she known about my TG urges and crossdressing when we first met, she would not have married me and I have to respect that.
I hope that you will find a solution to your predicament.
Amanda