It's not just you Molly. I am 45 and I have felt the same way, plus had a lot of crying spells after the surgery that had never had before. In researching it, I found that it's mostly hormone related, and you can't replicate your hormones after your organs are removed.
Through the last year and a half I've noticed a lot of changes that are hard to describe. I was an emotional wreck for about 10 months, and I've had a lot of short-term memory loss, inability to concentrate, feelings of loss of maternal instinct. It's really hard to describe but I don't feel like I did all my life, and not in a good way. The problem is that you know you don't feel the same, but outwardly you look the same so no one can see the difference. It's very lonely.
I read that the removal of the uterus causes chemical changes in your body. If they save the ovaries, the damage to the blood supply caused by the amputation of the uterus often causes a decreased ovarian function. It's a chemical shock to your body and you are deprived of the hormonal production you've had all your life.
You are not alone for sure!
Hang in there, take care.