If you're lost and don't know who you are any more, she's right. YOU need to find yourself again. I have actually been through this once. It isn't easy. there's a book called "The Road Less Traveled" ... Reading it will make you take a close, harsh look at yourself. It helped me.
I went through it. After a bad breakup at age 28, I had no wife, no friends, nothing. Like you, I didn't even know who I was any more. I had to rebuild my entire "self" from scratch... and it sucked and it took a long time.
On the other hand, reading the book I mentioned above made realize what a dick I'd been over the years. (It's a tough book to read... total truth in there, man) You have a golden opportunity to become the man you've always wanted to be. That's exactly what I did.
Start with something small and OWN it. Make it a YOU thing. Begin with THIS is ME... this is MINE. It could be a hobby, a personality trait... anything... just make it yours and OWN it. (I wrote a book, because I'd always wanted to be a writer... that's what was MINE) but seriously... you have nothing to offer the relationship you're in until you're complete and whole by yourself. Only then can you share that with your wife. Until you have something to share, you're just leeching off of her. She needs a partner, not a hanger-on. Good luck to you.