Happy Birthday, and come on! 43 is not old by any stretch of the imagination, and I mean that!
Listen man, Marianne Faithfull (legendary British Rock girl) is coming up on 56, and has just released an incrediblely cool new CD, entitled "Kissin Time" (I love that title). She and a lot of people in their 50's and 40's have more going on for them than a lot of folks in their 20's and 30's. It's all relative. We are, all of us, wines that will either improve or sour with age. The choice is ours.
And remember, we ALL are going to get there, sooner or later. The main ingredient in the recipe for a long and happy and productive life, filled with love and long-term friendships is...time. Kiss it!
Many happy returns of the day to you.