I think you can make those 3555s work. 1535s might be a better choice, but since you already have the 3555s and they're 30" long, I'd load them up until they do fly right. Next time, I'd buy some 1535s and compare them, but for now, try some 175 and 200 gr points and see if that doesn't improve things a lot!
My 3555s are cut 29.5 and I'm only drawing 28" to your 28.5, but my bows are a couple of pounds heaver so I believe we are close. I think if you raise the brace height a bit, possibly raise the nock height a hair and try the heavier points, you will see quite an improvement.
I like to have a variety of points on hand, but I understand you may not want to buy 3 or 4 packs of different weights. If you'd like to try some different weights, let me know and I'l send you one or two each of 145 - 225 gr field points. Once you get one that flies well, I'd just shoot that combination until you start getting nice tight groups. Then find a place where you can shoot at 20 yds and see what adjustments you have to make.