I am 36 years old, and have forgotten a lot of math from high school, of which I only took up to Algebra 2. However I am teaching myself mathematics and am now, completely fascinated with the logic and beauty of it, but pitiably I am only now beginning to end Algebra 1. I've a long way to go yet, and have the Saxon method at home (Alg.1, Alg.2, Advanced Mathematics (trig and precalc), and Saxon Calculus). So far I like it, as it is what I am accustomed to, having used it in high school.
But my question is if a calc text like Spivak or Apostol would be better than the Saxon Calc. I have found that Saxon is not mentioned in the same circles as Apostol or Spivak.
I think one's first exposure to calculus-no matter how gifted or ambitious the student is-should be a physically and geometrically motivated approach that illustrates most of important applications of calculus. Sadly, many people think that means a "pencil-pushing" or "cookbook" approach where things are done sloppily and with no careful explanation of underlying theory. That's simply not true. You can certainly do calculus non-rigorously while still doing it carefully enough to give students the broad picture of the underlying theory. I think in the case of a late beginner like you, this is even more important since your mathematical instincts are either undeveloped or so rusty as to be near useless. You'll need this combination of intuition and careful rigor to truly learn the material correctly.
The best example of this kind of book, to me, is Gilbert Strang's Calculus. Strang's emphasis is clearly on applications and it has more applications then just about any other calculus text-including many kinds of differential equations in physics (mechanics), chemistry (first and second order kinetics), biology (modeling heart rythum) and economics and a basic introduction to probability. But Strang doesn't avoid a proof when it's called for and the book has many pictures to soften the blows of these careful proofs. This would be my first choice for a high school student just starting out with calculus and I think it'll work very well for someone in your situation.