If everything you said is fine then there is only one solution. Using deductive reasoning and elimination. I would say its the game. Sounds smart, well I did stay in a Holiday Inn last night.
Though all kidding aside. The game seems to throw these issues at people from time to time. Alot of people have these problems. Its not your internet. Its the game and the way it deals with your internet. BO2, well don't be surprised if its worse. Warning you now. I hate to be the one to say "told you so". But I forsee trouble on the horizon.
I'm not sure if it was your other thread I said this or not
MW3 now has the 3rd most people playing behind MW2 and Black Ops. They've seen something like a 600% decline in population since April and a 400% decline since early July
Thing is, it's going to be hard to be placed in decent lobbies. Match making is having to expand through multiple continents just to put together a lobby. This problem will only get worse