Your nocking point is probably too low, and the arrow is kicking up off the shelf. If you aren't already, use two nocking points, one above and one below. If you don't, the arrow can slide down the shaft on release and give you all sorts of weird flight problems. I'd start with the top nock at 3/4" and go from there.
Cutting 1/2" off will get you closer to having the 145s work, but they might still be a little weak. You might need to add some weight to the back of the shaft. You could go with 4x5" fletch and it'll get them a touch stiffer. I think 1/2" will equal 5-6 pounds of spine.
Another thing you can do is add a footing. Basically you take an aluminum shaft of the right size and slide it over the end of your shaft. If you left your shafts 30" and added a 4" footing, you'd be able to go up to a 175 grain head for a total arrow weight of around 525 grains. With the bigger diameter of the aluminum, you'll need to adjust your nock height again. I can't remember offhand what size fits over a 3555, but if you use the search function, you should find it.