Hi there,
I am so sorry its been rough. The Australian Breastfeeding Association may be able to help. https://www.breastfeeding.asn.au/bf-info/special-situations
You could try lots of skin to skin contact, try and get him on the breast as often as you can. Him feeding will be much more effective at producing milk then expressing. Lots of snuggly relaxed time with the 2 of you.
You could get a lactation consultant to come and give you a hand too. Try different positions. Do you know if there was a reason why he had trouble latching on. Sometimes something prevents them such as tongue tie.
Hop into bed with no top on, leave him in a nappy and just let him lay on your chest. Or you could lay on your side and let him lay next to you with his face near your boob. Just enjoy each other, relax and see what happens. He may go looking for it. Relaxing is very important though. When he needs a feed offer the boob first. Skin to skin contact is very good for both of you and do it as often as you can. Try not to do too much, just spend a few weeks having all the time in the world to try and establish feeding.
All the best with it.
xxx