JoeBridg Welcome. I am sorry you have had such a dreadful time.
It is very isolating, so I do feel for you with your OH being away . You will find much support on here. Ondansetron certainly has helped very many on here. But do ask for a laxative - a side effect is dreadful constipation.
Also, an anti acid can really help with the nausea. Not sure if you're on one? Have you got kesottix just in case you get really ill again - you can get them from any chemists. At this stage, you know what liqids/foods suit you. Some that have helped people on here: flat full sugar coke, ice lollies, the juice of tinned fruit, Elderflower water, soda water, fizzy water, lemonade, fizzy orange, Lucoazade, Dr Pepper, orange juice (if not too acid), orange squash, sips of chocolate milkshake (maybe soya) and Robinson's fruit drinks. Foods of a sort:
nibbles of crisps and chips, cheap ice cream, tinned fruit, Scotch pancakes, baked potatoes, cuppa soup and slices of melon and mango.
Everyone: I have to go to a jolly funeral, and should be back on Sunday. Meanwhile, wonderful Mustang has promised to look in now and then and hold the fort (form the Pink Castle at the end of the Hyperemesis journey). Do take care in this heat.