If I had to guess, I would suspect ammonia poisoning. This is a very new tank, so your aquarium cycle has not kicked in. In new tanks, water can go from being ok, to having deadly levels of ammonia and or nitrites within hours.
Since at this time, you do not have a water testing kit at home, I would do a 50% water change today, to lower ammonia levels.
When at the store tomorrow, I would pick up a water testing kit. The API liquid freshwater testing kit, is the one I use and trust.
Often, after setting up a new tank, daily water changes are needed to keep toxins in check. I try to keep both ammonia and nitrites under .25 ppm.
Not sure how much you have read up on the "aquarium cycle", but its good info to know when trying to establish a new tank. Eventually enough bacteria will build up, to "eat" the ammonia/nitrites in the tank, so you will get a zero reading for both, and have happy fish.
If you need me to provide more info, on the "cycle", let me know.
I am not sure what the orange striped bottom feeders are. Do you know another name for them or can you post a picture of them. This may help in deciding if your fish are compatible.