Congrats on your little one's birth! It sounds like you are really doing a great job, despite the initial challenge of his early birth.

The ABA will more than likely have great advice. I'd just add that the best way to cut out the top ups is to bf your baby every time he looks in your direction for a few days. As long as he has been fine with weight gains and is having plenty of wet and dirty nappies try to bf as much as possible without the bottle. Maybe even go to bed with him for a weekend and do very little else other than feed, feed, feed. Your body will increase your supply when he is emptying the breast more often.

Let us know how you are going and GL with getting to exclusive bfing!