kim, i think you should try to evaluate the situation day to day with rizz, and put a call into your vet to discuss the situation with him or her. rizz is going through enough, and that takes a toll on your health, so i'd be sure to feed him well and give him fresh fruits, veggies - especially wetted broccoli florets and spinach leaves, and a daily vitamin supplement in both his water and food. if he stops eating from despair of losing his mate, you'll need to directly feed him with a dropper. the vet should be able to point you to a good feeding formula, or at least vitamin supplement. i use a combo of supplements (so they don't get bored with one and reject it), prime brand vitamins, nekton brand vitamins, and pro-feda brand.
if he just gets kinda melancholy, i would try getting another bird, but introduce them slowly. put the new bird's cage in another room in the house, but they shouldn't see each other, or be too close. this will allow them to communicate from a distance, getting used to each other, but is also a good idea just as a quarantine. rizz's immune system will probably be low from stress and the new bird could be carrying something that doesn't affect a healthy bird.
i am very sorry for the loss of your bird. i hope rizz is ok, and tell him we're sorry too.
oh, btw, if eggbinding ever happens again, gently rub the cloaca with a little vegetable oil, and keep the bird warm and quiet, temporarily removing any other birds to a seperate cage to let her concentrate on passing the egg. also give her a calcium/vitamin d3 supplement called calcivet, or if you can't get to a vet or pet store, give her an over the counter human calcium supplement called neocalglucon. if she continues to struggle, you may have to hold her over some warm steam and try to help massage it out, but that's pretty tricky.
A true lover of nature does not despair now that his mistress has turned a colder cheek.