Great advice by Andy and Paul. This game is hard to master but there is a wealth of great information in these forums - use the search for specifics.
However if you have been playing golf for 50 years, perhaps you are just tired - thats a heck of a lot of mileage!
Better clubs obviously help as they are more forgiving and accurate, and personally I would use only a cheaper ball (I used the Tour SD till master) as you will not get the bensfits of the ball with those clubs.
The two areas that you will improve your scores - short game and putting, These take notes on how far the ball flies and rolls depending on the lies and spin. Learn the distances of your wedges and then work on putting formulas. Master these two aspects and you will start to score a lot better.
If you want a hit and I am green just ask and we can talk through some aspects.