Oh, broken. I'm so impressed you found this site right away! I'm sure you've been reading through the forums and your fears of "too perfect" are based on the reality of the situations of other members. First, I want to recognize that each situation can be and is different in its own unique context and the groundwork laid both in the love and bond of the relationship and for the possibility of an A both in the relationship and the brokenness of the WS. I want to acknowledge that it is possible that "too perfect" can be your reality, before I move toward words of caution.
You are so early in the process. Given that it's only been two weeks you are likely still in shock about the situation and grateful that your WS's response is exuding such compassionate and loving indications of atonement. From what I've read on here, that's a great sign.
In my own experience, it's not necessarily an indication that you will be saved from the rollercoaster of your own emotions, or even from a latent "fog," gaslighting or lack of remorse. When I first found SI it was because I was a few months out and still had a gut feeling that there was "more." However, I fiercely used the initial response of my WS as an indication that my situation was unique to the point of being different than the similar patterns of behavior described on here. In those first months, my WS slowly backed away from the initial regret, bolstered her arguments that justified her behavior and TT'd me to death with the level of her involvement in the (second that I thought was the only) EA that got me here. For me, like many others who experienced similar patterns of behavior, I was totally humbled by my second DDay about a prior EA of which I had been given partial knowledge that totally freed WS from the wrongful involvement of which I was unaware at the time in wich her first EA happened. It was through the support of SI and my own recognition of self-worth that got me through that and onto the R forum, hopefully for good. That second EA discovery was the necessary realization that there was a pattern of behavior that contributed to her ability to rely on others for sexual or romantic attention and break emotional boundaries in our relationship. Without that realization we probably would have moved forward without addressing the underlying issues and straight into more A's, ultimately destroying the relationship.
I'm not telling you this to destroy your reality that he is being remorseful or to plant ideas in your head that there is more information or even more A's that will come out of this. I am sharing this because even if there are no more A's, this should not be considered an isolated incident. You haven't been together that long, so the indication of one A is enough to demand the same changes and steps to R in the M that anyone else on here has expected. Even one A, now that I have more experience, is enough information to realize that there is more than one possible opportunity realized and acted upon to indicate serious changes necessary to protect and maintain your M. You are right to question "why." The "why" that I am speaking of is not rooted in the opportunity presented at the time when your WS felt his needs weren't being met, but in the reason your WS chose to act on it and the reason he might act on it in the future. It's not linked to what you did or didn't do in the relationship, but to what he felt he needed to do outside the relationship that led to his ability to betray you in such a damaging way. The real "why" is the understanding of why he didn't request that you fulfill those needs or find a way to fulfill them on his own in a way that protected the boundaries of a healthy relationship. Though it may highlight relationship issues, it is more indicative of his inability to meet those personal needs himself or to respect you enough to share those needs with you so that you could determine if it was a relationship issue or his own brokenness. I can't imagine how tainted your first year anniversary was in the wake of the realization of 22 texts on your wedding day, or how tainted future anniversaries might be.
In the first month of DDay 1, my WS and I talked at length about the relationship. We focused on good times and misperceptions we both had and really connected. I was driven to prove to her the love and compassion she felt was missing from me. I felt guilty that she didn't feel "wanted" or was compelled to make independent decisions about how she was supposed to "be" in our relationship. I don't fully regret that now, but looking back I realize that I didn't allow myself the courtesy of realizing the whole truth, which revealed her own brokenness in contributing to her perception of the reality of our relationship. Her inability to feel "wanted" by me was actually orchestrated by the ways in which she was broken upon entering our relationship. Though it contributed to ways I interacted with her that made her feel unwanted, I was initially carrying too much of the burden for her independent decision to have EAs.
So, I caution you to brace yourself. Read through all the wonderful sources of support and information on here. Trust your gut. Take time to identify your specific needs for healing in the relationship and let him know what they are and what your plans are if he's unable to meet them. Hold him accountable for your needs and find ways to empower yourself against the rollercoaster you will find yourself on, even if it's only the rollercoaster of your own emotions.
Also, I missed so many opportunities to gather all the information I found I needed later on to prove my WS's truth or lies. I stopped investigating or just investigating deeper and missed opportunities. I think that because she was so remorseful and seemed to try so hard in the beginning I felt it was disrespectful to do so. There are ways to recover deleted information from cell phones. There are ways to secretly monitor activities. I strongly recommend exploring and investigating as much as you can right now, even if only in an attempt to verify what he's telling you. It will help you out in the long run, even if it only proves he's being honest.
That said, I'm so sorry you are here. I hope that your situation is perfect and that he is being completely honest and continues to work hard at proving himself worthy of you committing to R.