Hi Purdyrose,
No advice really, just sorry to see you worrying so much. No puppy/dog would ever replace your angel but would have its own personalities in its own right. I know exactly how you feel as I too am experiencing the same feelings but we still have Badger with us at the moment, allbeit sleeping nearly all the time but no pain I am pleased to say, although the ducklings have perked him up somewhat so I hope a puppy will too, to a point, I am still thinking about it, mulling it over and over as you do! I am also worried about temperament, etc of a new dog. I think because we have been so lucky with our first loves it makes it worrying to think about a second.
I am always at home because I work for myself from home, although in the holidays I would take the children out and if we go to a theme park we would have to leave the dog by itself, Badger has managed fine with this over the years, so I am sure it would adjust, as yours would too. If we go out at night we have to have babysitters anyway, so it still wouldnt be by itself in our situation but I am sure it would, they adjust, dont they.
I think the main worry is that you are scared of other dogs, any in particular? Are you scared of puppies also? You need to think back to how you overcome the fear with the first dog, and why would anything be different this time? Have you been to see the pups yet? If not when do you go?
As I said before I dont have any experience, this is just my opinion, glad to see you are OK.