deebee, Great that you know so many devoted people that could rehome your birds for good. I don't, and they are probably going to be hard to find.

An all seed diet is bad because it's not nutritionally balanced, and under normal circumstances you would want a bird to eat more than millet and other birdseed. But in a situation where a bird is not eating well, the only thing that really matters is to make sure that he's getting enough calories to stay alive. So it's OK for him to have an all-millet diet for a little while if that's the only thing that he's willing to eat right now. If he only ate millet for months and months on end it would be bad, but for a week or two it won't do any longterm harm. You can go back to encouraging good nutrition when he's feeling better and eating normally.

sadly, but I feel I lost connection with this flock. Cuddles seemed to be the glue that kept us all together, the link, and surprisingly even the leader, and now she is gone. Other birds just ignore me. Not sure what to do about it...

Try to focus and make a decision....
It's sad but needs you to do it
I feel for you

I wonder if attachment to a human is a quality that is trained or just bird's personality? I had two birds attached to me that I never trained this way.

I think it's learned, but it's possible to teach them without really being aware of it. Birds need to feel like they're part of a flock, and when there are no other birds around or very few birds, they will form a flock bond with humans. You have so many birds in your current flock that they don't feel any need to bond with you. Holding treats in your hand for them to eat (like millet spray) might help improve the relationship.

what about your birds, Carolyn? Are any of them bonded with you?

I saw what the problem is. Heartbroken Trillie tries to get attention from Stella, whose boyfriend Tator Tot protects his lady. There were 2 girls who were flirting with Trillie (with no BFs around) but he picked the wrong one.

and here comes the problem. yes, usually people who have great relationship with their bird do not own many birds.
Our situation was still pretty good before this tragedy. Cuddles who was attached to me, then Bella who liked to hang out with me occasionally, then some bird kids were landing on me rather often but didn't allow me more. Everything was satisfactory to everybody (except my tiredness and inability to commit to other life responsibilities)

Cuddles came from the house where she was the only cockatiel but they also had another bird. We/they (her and Trillie) had very happy times before all the chicks were born. I really made a mistake when kept the chicks. I always had a feeling Cuddles and Trillie would have been happier without any other birds in the house.

I looked thru the calendar with photos that our bird store issued a year ago, some people have cockatiels, I didn't see more than one cockatiel on the pictures, and most people have a flock consisting of different species. Not sure how this would be helpful to me in terms of possible rehoming

thanks Jan
I won't do any changes in the near future. This needs to settle a little bit

About half of my birds are bonded to me and the other half aren't. All of them will take food from my hand and will step up on my finger at least occasionally, but some of them are kind of hand shy and would rather step up on a stick than a finger.

The ones that are bonded are mostly the ones that I got when I didn't have so many birds, and the ones that I raised. Even the ones that I raised vary in how bonded they are - Snowy and Henry are pretty affectionate, Teela and Squeebis not so much, although they will let me pet their heads sometimes.