I am just back from a weekend away and have just read through this thread.
You must be exhausted with all this breastfeeding and expressing Berolina. By the sounds of things you do have a good supply of milk - the amounts you get are good. Sometimes you will only get a little which is totally normal. Please do not sit for an hour on the pump. I agree with Tiktok that you would be better using that time for skin-to-skin.
When you are expressing (which I think you should consider reducing now), keep switching the pump from side to side as the flow slows. As you express on one side, the milk lets down on the other. Switching frequently means that you express faster. I expressed regularly to doate milk (hand expressing) and got various amounts. I would store it in the fridge over 2 days then freeze it in batched of 2-4oz. Each amount I got I would put in the fridge and when it was cold I added it to the bottle that I was accumulating milk in.
I think that there is nothing wrong with your supply of milk now, it is your supply of confidence. Some of your babe's behaviours are typical of a newborn and do not mean he is being deprived of milk. Latching on, coming off, crying and apparently fighting at the breast are pretty common behviours of most babies in the early days. Instead of reading that as a sign he needs EBM or formula, just stop the feeding attempt and calm him down. A screaming baby will not breast feed. Cuddle him patting him firmly, massage him, bathe him, rock him in the pram. Anything that you find will calm him. He may even fall asleep. Let him rest then wake him later if need be. As he establishes all breastfeeds he may want to feed frequently. Again do not view that as a lack of milk. Not all breastfeeds that are sought are for milk alone - it is comforting for a baby to be at the breast and that is what they are looking for.
By having him skin-to-skin for the majority of the time you will pick up on his feeding cues. A baby wrapped up s;eeping may well start to show signs of wakening for a feed but if the breast is not close by may not fully wake and just go back to sleep again. That is the purpose of skin-to-skin. It is so important when trying to get a baby established on the breast. It does not mean you will have to do that forever
He sounds as though he has had lots of good feeds so he definately can do it. Have confidence in yourself not to resort immediately to the bottle. Be aware though that he may well want to be fed within an hour of the last feed. That is normal and is much more effective at building up your milk supply that expressing is.
Breastfeeding whilst in the bath often encourages babies to feed well.
I'll stop now as I am bombarding you with info. You are doing really well ensuring he gets breastmilk. I think it is time to take the next step and try reducing the number of times he gets the bottle. A baby will always suck a bottle even if they are full of breastmilk.
Think of when you go out for a meal. You may be stuffed full after the main course but when the pudding comes (which is different), you can always make room for it. A baby taking a bottle after being on the breast does not mean that he did not have enough at the breast. It is just something different.
You will get there, honestly