I agree with everyone else's sentiments, and I think it will be really good for you and your home to have some of that constant tension taken away. Not every animal will fit in with every family or home. There is nothing wrong with rehoming a pet when it really needs to be done, as long as it is done responsibly and with compassion, the way you obviously did.

I have always had large dogs as well, and in my experience they tend to be more laid back and easygoing, at least once they are adults. Not to say they aren't ever boisterous or get into things . I have nothing against smaller dogs by any means, I love them all, but like you I'm more accustomed to the big dogs and they are the ones that most attract me.

Don't feel guilty, you did the right thing for all involved