HpprKM, I kept bursting into tears on/off all day long thinking of what you are going through, thinking of the times when we lost our beloved furry babies, pets are family, they grow into our hearts.
Anyone who has ever had a pet will know what you are going through right now BIG, BIG HUGS
Of course you can never replace your Tillie, but you have so much love and warmth to give, it would be a crying shame if you decided against having another special little friend in your life.
Holding you, just let those tears flow freely, you need to let go of the emotions, and it will get better with every day, you will always have fond memories and know that you did the absolute best for Tillie, she knew that alright, she was a clever little soul.