It seems to me you are frightened of your boss. That's one more good reason to resign. Resigning is a very formalized and straightforward action. You draft a mail/letter which states that you resign, you deliver that letter to your boss, either by registered mail or in person. In any case, make sure you have a proof of reception. Maybe print two copies and let the boss sign both, one for you, one for him. If he refuses to sign, get a colleague to be your witness. Then you serve your required notice.
If he threatens you with bodily harm, you leave immediately and report it to law enforcement. If he tries to "guilt trip" you into staying, you only repeat what's in your letter: "I will resign, the decision is final, my last day is x". Don't go into a discussion about why and when. You don't need to explain yourself.
If it becomes unbearable, check with your local employment laws if it is lawful for you to not serve notice. This will of course burn a bridge to your current employer, but I think your mental and bodily health are more important. As a last resort, go to a doctor who you trust and get yourself a sick leave.
Remember: If you resign now, you have (worst case) 1,5 months of notice period left in this madness. If you don't resign, you'll have to work much longer under that toxic boss. Fear should have no place in a professional environment.
Edit: If you get called into some 1:1 meetings where you fear something fishy is going on, you can demand that someone from HR sits with you in the meetings. Of course only if your company is big enough to have a HR department.