Oof, reflux is a bitch. DD had silent reflux, we were watching for it as both I and my mum had it, so DD was diagnosed at 6 weeks. She was prescribed ranatadine which helped a bit.
Things that worked: ranatadine; sleeping in shifts like you do; expressing in the morning for the 10 pm-ish bottle given by DH; putting a wedge under her mattress - at one point she was propped in the v cushion to sleep as well. Sling, sling, sling. Go to baby groups, there's always someone else who has a refluxy baby and you can compare vomit schedules 
Things that didn't work: anything marketed for colic; going dairy free. Didn't try cranial osteopathy as it's bollocks and manipulating your child's skull won't make her oesophageal sphincter mature faster.
Don't worry about sleep associations. I was rigorous with bedtime, even though it meant standing in the dark for bloody ages, picking her up very time she choked then putting her down when she was calm. But she was in pain. Just relieve the pain and they'll sort themselves out.
Are you pumping, as an alternative to formula? I used to get up at 6 to do it, PITA but worthwhile. Good for supply as well.
FWIW, DD's reflux went away at about 18 weeks. I thought I'd never get to put her down, and that she'd never stop moaning, but just last night I breastfed her before bed and she fell asleep in my arms (a rare occurrence) as I was singing to her, and it was just FANTASTIC to do be able to hold her peacefully on my terms and get to gaze at her and enjoy having in her arms. Hang in there