Employer “phased” my job out, not even a 24hr notice

I had never been in any type of trouble at work. No counseling sessions, no warnings, no write ups. They claim my position is phased out and I don’t see how. Business office manager for a nursing home. You all know those are needed for processing payments, billing, etc all kinds of things. Anyway— I lost my assistant last month when she stepped up to another role. They posted that listing and me and the admin interviewed several people to replace her. Then all of a sudden corporate froze the position, took it down. Then Monday it went back online and yesterday afternoon, 30 mins before time to go, the regional VP sends a document to my admin stating if I don’t step down (with a pay cut!) then tomorrow (today) is my last day. The story they’re telling me is a corporate or regional person will be splitting about 4 or 5 faculties and I assume it’s all about not paying those four or five office managers salary anymore. Is this not crappy?! Not even 24hr notice. And they require us to give a 30 day notice if resigning. They offered me THREE WEEK severance pay at my current rate if I declined the big pay cut position and I’d have to sign to not seek legal action and etc. a friend told me before signing it I should ask an attorneys opinion. I have never been treated like this before and it’s not just me. There’s been some shady stuff going on. A separate company just took over our dietary department and was already over our housekeeping. It won’t surprise me if they are being sold. 😩