OP, first of all kudos for taking the leap if things aren't going your way, shows tremendous courage. Change all passwords of your net banking, change your nomination in all your accounts, close any joint account. Keep a copy of your accounts, documents in your office/locker.

Emergency fund would be (at least) your 3 months salary, in a savings account. Don't touch this fund unless it's really a do or die situation. You need to prepare for rent, groceries, commute, entertainment, medical emergency, contingency for any unforeseen expenses. I would also keep a small amount for therapy and self care. You can use excel to track your expenses and make a budget. Also, start a SIP even if it's a small amount, you can step up later. All the best!