So sorry, that must be disastrous on you. I likewise don't trust anyone to watch my parrot (except my old room-mate, who is also a parrot owner herself), but sometimes traveling is unavoidable. I hope you find a way to get over your loss. It is very devastating. As for a new parrot, I am not an expert but you have to introduce them slowly. First just have the two cages in the same room, but opposite sides. (Dont have them out at the same time, and dont let the one you take out, stand ontop the other one's cage). As the days pass, slowly move the cages together, so that they are eventually side by side. Then after a few days of being this close, hopefully they will be used to each other and you can see what happens when you put them both together in some neutral place. Keep in mind that the pre-existing parrot may not consider common things to be "neutral". For example, if you have a tree perch, he may think it's his own territory and he may attack the new bird for being on it --- you might have to get a new tree perch and use that as "neutral territory".