Thrawed and Frozen BM

Hi all mum, I would like to know on how should I mix the feeding for thrawed bm and defrost bm. Currently I pumped around 3 to 4 hrs interval. Have around 400ml exceed each day based on my LO intake. I will freeze about half the quantity and remaining will put in fridge for the next 3 to 4 days feeding. But I will also defrost 1 packet of frozen bm for each day feeding too and my frozen packets are growing everyday. Meaning one day feeding will have 1 packet frozen bm and 2 to 3 packets of ebm that pumped 2 to 3 days ago.Not sure whether this method is correct or not and would like to hear more advices. Thank you.