I think I know someone who has it, but I know they already have all of the achievements and I don't think they would want to help :/ I'll see if any of my other friends have the game and would be willing to help though! Thank you for that advice!
A word of advice, if you can find someone who has the game and needs to do the online as well, do it. It is much more enjoyable with others. I found the solo online story to be a little aggrevating (and offered very little XP), so the side missions are a better choice and more enjoyable in co-op.