Vectac
While 46 is quite old in this game it is not impossible. I have known several guys between the age of 40 to 45 get jobs simply because the airline knows that while it may take more time and money to train you....you are more likely to reamain with them for the next 10-20 years.
It is most likely that it will be a turboprop or turbo/jet mix airline that will employ you.
Also while it may take less time and money to train a 20yr old the airlines most likely to employ you are but training fodder to the younger types who want to fly bigger jets in the long run and are always moaning about the lack of prospects etc etc
Age can work in your favour as some ailrines dont want spotty 18yr olds at the pointy end when the customers want to see a wealth experience flying them around.
It may that your flying hours won't be high but your experience and man management skills should be at that age and this counts for alot nowadays age flying with pilots, cabin crew and passengers from all walks of life.
Dont give up or give in and despite what some have said dont loose sight of what you want to do or the many pleasures this career brings (be aware that a lot of sh1te comes with it also but is only 5% of it).
My only advice is to target your airlines carefully and seriously consider air taxi either as a career (hard but rewarding) or as a route to the airlines.
Happy New Year and Good Luck.