This is so normal and it happens to almost every couple that move in together. The every day stress and tiredness just kill the desire and energy.
But this mustn't lead to forgetting about each other needs. Make some room for romance from time to time, so you wouldn't forget why you moved in in the first place.
Everything will be just fine. The first years is the hardest. If you manage the first year, things will go smooth after.
What saved me and my boyfriend is having too separate rooms :). It is essential :)