Need tips

Got diagnosed with UC last month and currently on budensonide and lialda. In a bad flair and maybe a viral infection. Neck and upper back are stiff, headaches and runny nose. Tried drinking IV and lots of water but vomitted it all plus diarrhea.

Any tips to cope with these symptoms? When should I go to the ER. Headaches aren't really bad and I don't feel very feverish but really dehydrated.