Can't focus - attention span gone - is this Mirena?

I've always had an extremely sharp mind, but since giving birth 3 years ago, which coincides to when I had the Mirena inserted, I've lost my brain. I work as an executive in business. I sit in meetings, the same meetings I sat in for 10 years, and now I space out. The whole room could be carrying a conversation, and I can't remember what the last sentence is someone said. I thought it was post-baby memory loss from lack of sleep with new baby. But 3 years later, and I get 8 hours of sleep a night, can't be the reason.

Has anyone had this same feeling? Has anyone had the Mirena removed and turned back to normal? It's such a convenient birth control, but I'm not sure it's worth my memory loss. Is this what Menopause is going to feel like?

I also have a "funny" feeling "down there" like I have to pee, or that my bladder is full. I even went to the bladder doctor thinking I had an invection and he said, nope, no problems. So I asked my OBG and he said it might be me feeling the hormone release. That's when I started to put two and two together about my attention span and memory loss.