Is it normal that i get too emotionally attached to every dog

I had fostered this fun loving, naughty, handsome 3 months old german spitz for a day. I already have a 6 years old spitz at my place. He is very attached to my family and me and is also very possessive. And whenever we foster a puppy, my dog "jojo" gets upset, depressed. But me and my dad decided to adopt the cute puppy that day itself. We fell in love with this puppy, its not the first time this has happened. Later keeping him for a day, I realised that its a big big responsibility to have another dog and especially if you are upsetting your previous dog. Plus, I have my end semester paper for masters degree and research paper submission in another 2 months. Then, Nobody is at home in the afternoon and only available in the evening which means I have to keep these two beautiful souls in different room locked for 4 hours. This causes more tension and trauma to me as well the dogs. My dog jojo is well adjusted to this schedule of ours(not being at home in afternoon), so he sleeps throughout the day. But this new puppy is in his formative years and cannot be neglected and is active so cannot be locked . So I told my dad to put him up for adoption and then we found a family and gave him to them. Me and my dad cried a lot, its difficult for us to not think about the puppy.
Now I am just trying to convince my dad and me that its better that he is with his new family and not with us as we would have neglected him. My dad is upset and really sad, even I am sad. I am feeling guilty and miserable, just wondering was I wrong? I took a practical decision I believe As the puppy got a new home(not getting neglected) and my dog is normal now but my dad is sad. Plus we still remember the puppy every now and then.