Unable to withdraw

I know that I am stupid and was cheated. At the beginning, there was a chat group created by Gao Jianhong, but I have already quit the group. A stockholder Zhang Hetian added me and introduced Liu Yixin, the chief analyst, and Lin Shihan, the assistant. I just started with a common account, and it turned out to be profitable. Two weeks later, in March, Liu Yanxin and Lin Shihan kept inducing me to join a charity private equity plan, and it was monitored by the Financial Supervisory Committee. I was suspicious, and then Liu and Lin kept luring me to join. At the beginning of small investment, I sent money through a manager Zhang, who kept saying that I could not make money this way. As a result, I joined the program, and then they asked me to transfer money through Manager Zhang. At the beginning, I made withdrawals normally. Later, when I withdrew, Manager Zhang said that I had to pay 20% to the charity fund, otherwise I would not receive the money. I was cheated for 800,000, and he threatened me to freeze my account. I know I am stupid and silly, please help me.