Take a look at some of the other questions in tag sugar-daddy. Your experience is not unique, sadly.
The tag description shows what I think is happening to you:
A sugar relationship is often used as a setup for more ordinary fraud by enticing the sugar-baby as a mark. The scammer suggests to the sugar-baby that he likes her and would like to send her something, this elicits access to the babys accounts or gets her to act as a money mule by cashing fraudulent checks, buying goods with stolen financial information, or other fraud. The sugar-baby thinks she is getting something for doing little more than flirting with someone or sending pictures, in reality she is being victimized and stolen from or being used to launder stolen money.
The money your sugar-daddy sent you was either not his in the first place or was from an illicit source, like drug sales. You did the right thing to contact your bank, that cashiers check is probably going to bounce or get pulled back.
The threats to take you to the FBI or police are just that, threats. This is not a person who wants ANY contact with the law.
Keep records of your contact with the bank, get some screenshots or paper copies of your statements. Keep the money that has been sent available, don't spend it. The bank will suck that right back out of your account when the check bounces.
Being a sugar-baby is not a great way to make money. It's not that lucrative and exposes the baby to a lot of personal risk. As noted in the wiki, a lot of the actual sugar relationships are designed to very tightly control the sugar-baby. The relationships are inherently controlling and expose the sugar-baby to risks for being draw into scams and fraud.
If you're hell bent on staying in the sugar-baby game, find a better way to take the money. There are good online payment services that are NOT attached to your bank account. These services would be both generic payment platforms as well as "camgirl" sites designed to support sugar relationships.