Sorry for your loss, You tried and that is all that counts. He had a home to call his own before he passed and that is a lot better than being in a cold cup.
I lost a rescue yesterday too. He lasted 2 days then I came home from work and he had passed. It is never easy but at least we tried.
Just because I'm in a cup, does not mean to pass me up, all day long I sit and stare wishing you would take me there. To your home to set me free, in a tank would mean worlds to me. I'll be your friend and loving pet, buying me wont bring regret. I'm just a Betta can't you see, all I ask is you could too love me - CandiceMM