If it's reflux I promise you it will improve when she's sitting and standing because it will take a lot of pressure off her poor throat and it will make lying down more bearable. Also weaning will help...
If it's that she's very oversensitive to everything then it should improve as she controls her environment more.
If it's colic then babies do grow out of it!
That said over the internet we have no idea what it's really like for your, we can only draw on our own experience of either having or caring for very challenging babies and we're definitely not qualified to diagnose whether it's reflux or 'just' colic/fussiness/overstimulation. We can, however, suggest strategies you might not have thought of. I found MN years ago because an ex-charge had a weird unexplained rash that just would not go away, didn't seem to be related to food, temperature, skin-care products, plants....you name it we'd tried to eliminate it. The hive mind suggested changing the brand of washing powder and bingo! Sounds obvious in hindsight but we'd totally missed it.
Honestly a needy 11 month old is very different to a needy 3 month old and that latter is much, much, much more difficult to cope with though. The old needs will be replaced by new ones!
Even if the situation doesn't improve you will be able to find a carer who can cope with your DD, though.