A shaft "loads" or stores energy on the backswing and "unloads" on the downswing. Contrary to many beliefs, what you are experiencing could well be the shafts in your clubs. Many people think a too stiff shaft wil not "kick" and therefore leave the shot to the right and the too whippy shaft will "kick" early and leave the shot left. Actually the opposite happens. A too soft or flexible shaft will cause the clubhead to lag the shaft and leave the ball to the right (for the right handed player) while a too stiff a shaft will unload early getting the clubhead to the ball before the shaft with all the stored energy expired leaving a shot to the left, usually low and without much power. The experience many have is after the true thing happens, they start compensating in their swing causing the opposite error.
However, let's check some things before we start totally blaming the club's shaft. First with the club, are the marks on the face of the club on the toe or heel and are your divots deeper towards the heel or towards the toe. The marks on the face will tell you two things: 1) is the club length correct for your stature and swing and 2) is the lie angle correct. These can be easily checked by an expert clubfitter. So all may not be lost, clubwise, because these are easily adjustable in the hands of an expert fitter and club repair expert.
Secondly, let's be sure we are swinging correctly. Is the club swinging on too much of an inside to out path or an outside to in path? The inside to out path can result in a shot starting to the right and hooking to the left because the club is swinging in an arc around the body too much and allowing the clubface to close too much. If it is an outside to in path then the stiffer shaft could be preventing you from opeing the face as in the past (possibly) that reesulted in a straighter or slightly fading shot. Also check your grip and see if either or both of your hands are rotated too far to the right on the club. If so, that too could cause the face to be closing too much causing a hook. If any of these are found then simply try to do the opposite to make a different result.
The Great Silver Scot, Tommy Armour wrote in one of his books in the early 20th century (circa 1930's) that in no game or sport is the equipment more vital to the success of the player than it is in golf. Therefore the bottom line is this. Take those new clubs to an expert fitter. Get fit first and then see if the fitter can recommend and fix the set you bought. Although an expensive lesson, it will much easier, more enjoyable and better scoring if you play with a set of clubs fit for your swing than trying to adjust your swing to an ill fit set of clubs.