I have had four refluxers, three on meds for it, two of whom were classed as severe (ie, choking, breathing issues, and we were admitted to hospital a lot while they sorted out meds for them, tube feeding etc).
mine were also found to be dairy allergic, so I had to adjust my diet while I breastfed, and then DD2 and DD3 went onto soya formula from 8/9mths, DS1 was ok with normal formula, but DS2 needed hypo-allergenic stuff......pregomin.....from 4mths.
I found the for sleeping, they were best being propped up. DS1 in fact slept a lot in the baby swing we had, or his pram, as I could adjust the back.....not ideal I admit, but we all slept, and he slept better like that, so we were happy.
with DS2 tho, I actually bought a baby alarm with breathing mat attached, and he stayed in the crib, and then cot.......still with the matress raised, but on a mattress. I have to say, I wish I had had it for all my children........I was much more confident with him than any of my others, and I think it was because I knew it would alert me if he needed me.....
it is scary being a mum of a refluxer, but try to relax as much as poss. your mum is right........if the docs are in any way worried, they will admit you both. it will get easier on you tho once he is able to roll himself...
good luck......it won;t last forever, altho at the time it does feel like it.