Today i was talking about something similar: A girl friend (not a girlfriend) of mine lost her beloved cat last year, and then got 3 new cats. She clearly likes the new cats, but it isnt even close of how she use to love the old one. She would skip dates, get home early, couldnt go out deppending on the hour, all because of that cat. Now, she is much more "free".
Then, I started to think about myself. Three years ago, my rottweiller (the sweetest dog I ever had) died and my chihuahua was very very sick. She died as the age of 10, while the chihuahua was 16. After she died, the little one didnt last much longer, and died too. I was devastated, so, i didnt wait much to get a new dog.
So I got my labrator. He is a cute, insane, hyperactive, smart as f*** and very, very needy dog. And sure, I love him. But i always got the feeling that I dont like him as much as i liked other two. Possibly because i got him for the wrong reasons.
I always think that i should have waited more to get a new dog. But, well, too late.
So, i think you should be sure that you are not doing this for the wrong reasons, like I did.