The symptoms you are experiencing are related to UC and the drugs your are taking.
Can ask your GI specialist to give a drug against nausea
Although you are not eating solids, you can prepare soups as they are nutritious and won't give problems when passing the motion. Metallic taste
could be a sign of possible stomach problems (gastritis
, GERD, ulcer,etc.). Can start antiacids and omeprazole
and ask GI to do fibrogastroscopy.
All the best!