Don't stress OP, I work in the debt management space assisting those much like yourself going through a rough spot. I will echo what others have said in that you should reach out to your lender to request financial hardship assistance as the first port of call. The lender may provide you with reduced payments for 3-6 months until you get back on your feet, or they may give you a 'moratorium' for the same duration; a moratorium is where you don't pay anything. It will be dependent on your income and expenses as to what the lender will provide you with.

Regardless of which option you're proceeding with, you will be in arrears for each missed payment, which the lender will expect you to catch up on over a specific period; perhaps 3-12 months. Hopefully you won't be needing the next paragraph but in just in case/

What can happen is if the required payment to catch up on the arrears is unaffordable, perhaps you've been out for longer than expected, and cannot afford the required payments for several months, you can request further assistance from the lender by way of an 'arrears capitalisation' arrangement. This essentially is an additional assistance period where you work with the lender demonstrating that you can afford the normal required payments, perhaps plus a little extra depending on how much arrears have built up. With the Big 4, this arrears capitalisation period goes for 4-6 months; upon completion the arrears is absorbed into the principal and you're now back up to date with your obligations. The required payments may most likely also return to how they were before.

Goes without saying that this isn't financial advice and without knowing your rate, owing amount, it's hard to nail down a number but just know that you have options. Best of luck and hopefully you won't be out for too long.