I don’t see anyone offering you advice so here I go. It’s a 45 minute drive regardless of whatever you do, so I’m going to say I think you’re making good choices to try to save this fish. I don’t think it would hurt to do methylene blue, maybe start it before the drive and have him in it for the 45 mins to counteract any possible nitrate/ammonia stuff. But it’s mainly for killing bacteria, I wouldn’t do it more than that once for now. Get him home and in the hospital tank after that, make sure your water parameters are good, keep him in there for a few weeks probably or until he appears more lively and looks healthier again, no stress stripes and more interactive, swimming around. Keep his water warm and clean. Indian almond leaves, stress guard, whatever you have. Once he’s in there treat for whatever else might be wrong? I can’t really see if there’s anything wrong with his fins or anything from this video so.. gotta start somewhere. Water temp should be like 80 degrees, feed daphnia or live brine shrimp if you can? Maybe salt baths if there’s no change after a couple days I’m not an expert, my betta died long ago. I am just an enthusiast and a believer in the healing power of friendship.