A.C.
R.-
I am sorry that you have to deal with this all at the same time. Weaning can be an emotional time by itself--it was hard for me and mine was 18 months!
You've already had a major victory since you've found a bottle that he will take. Now it is time to wean him from the emotional aspects of weaning. Start by eliminating those sessions which are the least emotional (i.e. not nap- or bedtime). Try mixing breastmilk with mixed formula and gradually changing the ratio to give additional familiarity. Use a pacifier if he will take one. You might also consider introducing a sippy cup--the novelty of it might distract him. Mine started with one at 5 months and didn't take a bottle after a year...the nighttime pacifier battle is another thing!
I believe LLL recommends removing one session "time" per week, so it could be 6-8 weeks before he is fully weaned. I don't know if you have this much time. Be sure to watch yourself as well for signs of plugged ducts and/or mastitis.
Be as consistent as you can about the times he gets formula and the times he gets to nurse. There are going to be days when nothing will do but mom, but he'll catch on quick enough.