High Sierra Topix

I ordered the Osprey Aether 85L, which according to the measurements and everything I've done is the correct backpack for me. Really the only issue I have is the hip belt not clipping (as I've mentioned before, I am a big guy). I did however find a hip belt extender which should do the trick.

From everything I've looked at with the backpack, it fits fine, it's just the top part seems to rub on my neck. From what I've read you are supposed to get a bigger pack, but this is the biggest pack I can get, so what exactly are my options.

Am I possible just wearing it wrong? When I get weight in the back is it going to lower itself down and not be an issue?

The best thing you can do is go to a local REI, and get fitted properly by a
knowledgeable sales employee. Buying equipment on-line, where fit
equals comfort, is always a very difficult proposition, think for example shoes.

I actually just figured it out, I had the back too high up, lowered it in and perfect. Definitely will go to REI though, at this rate I'll end up breaking my back after Day 1.