It's never easy finding out our adult child is in jail. My son is also in jail again. I have lost count of how many times my son has been in jail. This time it's for assault with a deadly weapon (knife) he could be looking at 16 years.
When our adult difficult kids are in jail we have to prepare ourselves for them ask us for help. Sometimes they want us to get a lawyer for them. I have not and will not ever get a lawyer for my son. They may also want you to pay their bail. Again, I have not and will not do this for my son. The only thing I have ever done for my son when he has been in jail is to put money on his account. I will not be doing that for him this time.
I know how this can shake you to the core. I know how the tears flow. I wish you did not have to deal with this.
The only thing I can offer you is this, your son put himself in a situation that did not end well. This is all on him, his choice, his consequence. He has to own it not you.
You still need to go about living your life. It's okay to be sad about it, it's okay to cry about it but don't let it consume you.