My (M39) wife (F36) admitted to baby-trapping me with our first child, is this fixable?

For context, I started dating my wife when I was 23 and she was 20. A little over half a year after we started dating, she got pregnant, and we decided to keep the child and to get married. As the title suggests, this was not a planned pregnancy on my part. I won't say it was easy to raise a kid when we were really just starting out as adults, but things worked out more or less. Since the birth of our daughter, we've had 2 more kids, both planned. Our daughters are now 15, 10, and 8.

Last week, my wife admitted that she had lied about taking birth control when she got pregnant with our first daughter. The reason she gave was that she was afraid that nobody else would love her or support her like I did. I honestly don't know how to wrap my head around it, I don't remember myself being distant or anything like that at the time. I know life hadn't been kind to her (to say the least) before we got together, but I guess I still don't really get it.

Before she confessed, I didn't really have anything to complain about in our marriage. It hasn't always been easy, especially since we had a kid before we were really ready, but on the whole nothing in my life has made me happier than my family. Before this, I would have said we had a very strong emotional bond, and I thought my trust in her was unshakeable. I thought she understood me in a way no one else has ever understood me, and I thought I understood her the same way. Before now, I never doubted that she loved me, she always put real effort into our relationship, so I never felt like she took me for granted. There are more than a few things I've given up for my family, and I work long hours to provide for them, but I don't think I ever thought it wasn't worth it.

I don't know what to think or feel anymore. On the one hand, the image I had of her has been shattered, and I don't know how to rebuild my trust in her. On the other, if I were to leave, I'd be throwing away my entire life. I know I should want honesty from her, but truth be told, there's a big part of me that wishes she just took that secret to her grave. That part of me thinks it was selfish of her to tell me, because she blew everything up just to assuage her guilt.

In the week since she's told me, we haven't really communicated much. I told her I needed space to process everything, and she hasn't pressured me to talk or comfort her, nor to put an act on for the kids. But I can tell she's anxious, and growing more despondent by the day. I want to comfort her and tell her I love her, but I don't know if it's possible to fix things, and I don't want to draw out my pain or hers if it's not.

TLDR: My previously happy marriage has been shattered because my wife confessed to baby-trapping me with our first child 15 years ago. Can I fix my marriage?