That is concerning to hear since a bolus of roughage could act as an obstruction (which then causes the bloat). If she is prone these issues, then it does make it more likely here. As I am sure you are aware the bloat is serious (especially if the stomach then twists, though this would be acute not something lasting for days) and you need to get things moving through the gut as soon as possible (otherwise steps need to be taken to decompress her, and possible surgically remove any obstruction). First step is to immediately remove any feed/edible bedding, if you feel that could be the cause.
If you can get her up, you can stomach tube/drench her with a laxative agent (ie lactulose, miralax, mineral oil, etc) or even a quarter of a pint cooking oil to just get everything moving thorough that gut. As well, get her moving (walking) and massaging of the sides. This most often will cause the built up gas to escape through the mouth or rectum. Once you have gotten her relieved of the gas, we will be in a better state and the pain should be reduced. I would avoid banamine with GI based issues like this since she will be more at risk of GI side effects from the drugs (ie ulcers, GI bleeding, perforation). Rather we want to relieve the bloat and if pain relief is necessary then we really need a vet to use injectable opioid (since they won't have adverse effects on the guts).
If this is more then a mild bloat, then you may have to be more aggressive. If she has bloated before, you might have experience stomach tubing her to relieve the gas pressure on the stomach (LINK, this is a goat example but the process is the same. Do take care though, since stomach tubing must be done carefully to avoid damage to the delicate gut but also we can't have the pig bite through the tube --since that would obliviously cause even more issues ).
If you haven't done so before then a farm vet is your best bet to help you and do this for her. And if there is any struggle, they can sedate her, give pain relief, and they can carry out a sterile tap the stomach directly if the tube cannot be passed. As well, they can evaluate her and let you know if there is a stomach twist (which would make her prognosis guarded to poor), and help you address that complication if it has arisen
Overall, the bloating is a red flag here that Barbie's situation is getting very serious very quickly. If there is possible obstruction, then you need to try and get things moving through that gut while you are helping to relieve the gas build up. If you do the above and are not getting positive results, then you do need to either take her in for emergency treatment or find a farm vet that can come out. (which I appreciate you have tried to do already, so hopefully this isn't as serious as we are concerned it may be but we have to have a plan if things are that serious). Also here is a link for the Housecall Vet database (here). The majority are companion animal vets but hopefully they can assist to advise you on someone nearby who can.
All the best,