Toxicity at workplace

I am currently working in a startup, and directly report to the Founders and CEO, my role involves dealing with salesperson operations and labours, the instructions I got from upper manager is that I need to be tough with them(the people whom I manage) and no need to talk in nice way, the feedback we(those who joined in 2024)got from the Founders and upper management that they talk very nice with salesperson, I didn’t believed in that theory that if we are managing someone and get work done from salesperson I need to talk rudely and be grumpy with them, but now I am looking changed in behaviour of my friends they are becoming what the upper management wanted and I now I don’t like much to interact with them, this is not the only part of toxicity each one of us have got the message or mail that they will terminate us, recently I got the same message on a very small issue that I need to change my attitudes towards the work otherwise they will terminate me they always give this threat of termination,

I am fresher recently graduated from Tier-1 Engineering college, I do not know much about corporate, I just want to know is that how corporate/startup works, now I am having second thoughts in all this maybe I am the wrong and that is how thinks works after I got the message of termination I do not know how to explain it but that message kind of just playing in my head I seem reading and not feeling good about, I don’t know if things works this way or not after the termination message I am having second thought that maybe I am the wrong person, I can’t share this with my family or any other senior colleague at work, every senior person is puppet of upper management, or they all have become that person whom these mental torture doesn’t matter, they don’t see a person as a person, I don’t if I am able to convey how I am feeling right now, just wanted to ask here am I overreacting maybe that is not a big a deal, but one thing I am sure I can’t be the toxic person which they want me to be,also leaving the job is not an option now