middle age crisis?

I'm 46 years old, nearing 47. A few weeks ago I was going through some old photographs of my wife and I when we first met/and married. I was struck by how young we both looked, and then thought about the years since, and the mistakes I made (not infidelity but responsibilities and financial). Since that time several weeks ago, I've been being consumed in thoughts of wanting to go back, be younger, actually by thoughts of wishing I could go back in time. Consequently I feel as if I'm lsing my sanity and am having a hard time functioning normally. Please tell me what's wrong with me and a possible solution before I completely lose it. Thanks