A lot of what you are describing sounds totally normal for a couple together as long as you 2 (for some of my relationships, that phase came a lot quicker!). I think it is pretty rare for 2 people to spend that much close time together and not have the passion die down a bit - I would not jump to the conclusion that she no longer finds you sexy or that the relationship is doomed to fail.
However, I think it is important that this is discussed - simply becasue it is worrying you. Something like this, what is probably just a normal "rut", could become more if one of you is harboring feelings of insecurity of resentment over it towards the other. THEN it could snowball into something worse.
But the fact that the sex has slowed down, is getting a bit routine - come on! What long-term relationship hasn't that happened to?