You described my life when my son was that age. My son was also refusing the bottle so I ended up spoon-feeding BM during the day and then BF throughout the night. It got a bit better after 8-9 months but still not like before 4 months. A friend of mine had the same issue with her son and she gave bottles of EBM when her son got distracted. They ended up with nipple confusion and exclusive pumping after 4-5 months. So she advised me not to my son a bottle at the time but I was sooo desperate that I didn't care so I tried all kinds of bottles but my son refused all of them.
Some mommies here used nursing necklaces successfully in these situations maybe you can try that.