Remember, his lying isn't your fault. It isn't a reflection on you. He CHOSE to deceive you. More than once. He had chances to come clean and he chose to continue to lie.
And his excuses are BS. He wanted to date young women so he chose to lie? He could have described himself as "middle aged but youthful man seeks somewhat younger woman". Sure, that may have weeded out women who don't want to date middle aged men, but how did his lying work out for him? He hurt you, someone who didn't deserve to be hurt.
I would not give him a third (or fourth, or whatever) chance. He knows lying is bad but selfishly did it anyway. That's a "nope" for me.