Middie, a "breakdown" is not very easy to "just" get out of and find a mindset to be able to explain why, how, and what is next to others. It "can" take more then 3 weeks for medication to take affect, that is, if he was given a medication that will work for him, not all medications work the same for people, some people have to try a few before finding the one that really "helps".

I know three weeks seems like a long time, but it's not like a regular illness when someone has a "mental breakdown", this could have been brewing for "years".
I know you want to see him, just talk, but often it is most helpful just to let his treatment providers take the time to work with him with no other complications. If he has been in the hospital getting treated for three weeks, it must be a bad breakdown and that is not something "you" can talk him out of or even help with.

As far as his father not saying much, the truth is that he may not know anything to tell you.

I am glad you are still sharing and venting and reaching out for support. Whatever you need to ask, vent, etc, we are listening.

(((Hugs)))
OE