Thanks everybody. Almost all the fish have stringy white poop so I've researched the suggestions and I have bought API general cure for Metronidazole and Praziquantel, and I've bought eSHa-ndx for Levamisole. I now have learned I should always have these in my cabinet for urgencies and new fish treatment. Unfortunately they can take another 8 days to arrive if I'm not lucky with shipping as one is coming from USA to UK, and the other just said 8 days unsure why.
Hi! I've used the eSHa-ndx and the eSHa gdex to treat worms, and I also keep shrimp, so I can attest that in my case, the eSHa meds did turn out to be shrimp safe!
I don't recommend buying meds to keep in the cupboard "just in case" though. I know you want to feel prepared for anything, but medicines do expire, and it would prove to be an expensive waste of money. There's also an understandable tendency to immediately reach for meds and try them out when you see a potential problem, without being sure of a diagnosis, and this can do a lot more harm than good, so having to wait for an order or go to a store first can be a good thing. Means that while you're waiting, you can research the problem more thoroughly, and make sure you're dosing the right thing.
My parameters are always stable, I always check for nitrates, good temp, and toned down lighting with duckweed at the expense of plants, lots of hiding places, I don't understand why little things always happen in my tank which are accredited to "poor water quality" in articles online, the only improvement I am aiming to make is getting a water distiller or an RO system which is practical for me, ( I can afford and use in a rented home where I cannot attach to the sink.) This is to soften the water, but I need to do more research on best mineral levels and hardness levels for my fish.
Worms are a nightmare. A treatable nightmare, but still a nightmare to go through when your fish are suffering and you're experiencing losses. Have been there! Can even link you my thread from when I was, if you like. There's useful info from others in it, along with my panicked stressing over it. I felt the same way. Was religious about water changes, quality diet, water testing, live plants and extra filtration etc - so when fish were getting sick and dying despite all that, I felt like a failure, and like giving up the hobby. It's not your fault. Many livebearers arrive to the store carrying a heavy worm burden, and they can seem fine for a long time, months even, until they're not.
The swim bladder - don't use a swim bladder medication (which med is it?) since all kinds of things can affect the swim bladder, including worms. It's likely that whatever is causing the swelling - whether that's the worms themselves, a secondary bacterial infection as a result of the worms, or something else entirely - is causing pressure on the swim bladder (which is an internal organ filled with gas) and hence causing the off-balance angle and swimming. Treating the worms may fix that.
Take some breaths, read up about the best way to go through medicating them etc, and try not to give yourself a hard time. This hobby has a steep and brutal learning curve, but you're obviously willing to do what you can to help them, and we will help where we can.
Next morning, 1 dead shrimp, poor thing. Can't even find the other one 
just dosed Seachem Stability into the filter.
