As Rockport says, 150 is not the weight of the arrow but the spine designation. The 150 computes to about a 500 spine. Depending on the length of the arrows, point weight, draw length of the bow, cam style, and draw weight these might not be stiff enough. But assuming they are then you need to have your bow properly and tune it to shoot those arrows. Part of the tuning would be to ensure the fletching isn't hitting the rest or cables which could be part of the problem.

I think you need to get to a reputable shop and get some hands on help, unless you know what you're doing. Many guys think mounting a rest, nocking point, and sight on a bow by a shop is tuning, but it's not. Basic setup and tuning are two different things and a shop can help with both.

Another thing a shop can do is help you with learning some decent shooting form. This is a must if you are going to shoot well. A bow is nothing more than a simple machine that uses a block and tackle system. As a machine it will do the same thing for every shot, assuming you shoot it the same. As such, even without being tuned it will shoot arrows to the point. They might fly ugly getting there, but most times if it won't group then it's a problem with the shooter not being consistent.