rufunias

Hi, I have two children under five and live in a large apartment but apartment nevertheless. I am having a difficult time trying to find the right dog breed. We used to have a wonderful Bichon Frise, but he stayed with some "surrogates" over a vacation and he totally changed his behavior. From starting to not play at all, to urinating all over, to constantly vomiting and defecating all over when we were unable to pay him tons of attention or left alone.We would only leave him alone on sundays. We had him checked with several doctors and they told us he was having some sort of nearvous disorder related to separation anxiety. We started medications and tried different routine changes, but it would improve a for some days only to relapse. So we had to give him to the "surrogates" were they can properly care for him. We had had 4 previous wonderful years with him.
But now my daughers are very very sad and so am I. Wondering if it was a poor choice of surrogates (that they changed everything he was used to and set different standards).
We really really want a dog to share our lives with. Any help??? Suggestions