NAH.

The relationship timing could have been a little better from both your sides. Neither one of you was ready to be in a relationship again. Some people move on quicker than others though, and this can cause friction. It's life. In your collective case some couples counselling will help. Arguing about it at home certainly won't.

Unlike most other people here, I don't think you're being an asshole or a raging bitch about this matter. Obviously the guy's grieving still and that's understandable but he's made a choice to enter a new relationship and that comes with a certain level of responsibility and expectation that the old one is over with. He's trying to have the new without moving on from the old, and it's also perfectly understandable, to me at least, that you'd want the old relationship actually over and done with so you both can focus on your current life together.

As it stands right now he's in two relationships, one with you and one with her, and that can't be easy for you. From a certain point of view it'd almost be like he's cheating on you. He's not, but the emotional/psychological effect on you must be strikingly similar - when he's with you he's also with her, how can you know he's truly with you if he's got a shrine to his dead wife in the bedroom where the two of you should be sleeping? That sort of thing.

Frankly, what he's doing there is not healthy for him at all. Whilever that room is as it is, and it is as it is for him, as you say, not for his daughter, but that is a convenient excuse he might not even realise he's using. Anyway, whilever that room is as it is he'll never move on. Harsh as it is to say, his dead wife's dead. She's not coming back. He has to face that and move on. He can't live in both worlds. He does need to box that stuff up and store it. Not throw it away, but just remove it from day to day life and visibility for his own sake if nothing else, and the sooner he does that the better it will be for him. That's true whether you're in his life or not, but with you being in his life then that's even more reason to. If he wants you in his life then he needs to accept and acknowledge that you're his future and that the past will only drag him down.

All that said, 10 months is a short time frame for that to happen in. People grieve at different rates and move on at different paces, and you can't expect everyone to move at yours. I don't think you're being an asshole about it, but perhaps a little insensitive with that expectation. But then again he's decided to start a new relationship so the expectation isn't necessarily unjustified. Again, couples therapy.

Regarding some of the other comments here... people these days love to wallow in their own misery and overindulge in overemotion. Don't ignore them, but don't take it too personally either. They're very immature at times.