Okay so there's the answer
If you click on the link in my sig that mentions how to cycle you can read up later about what is going on with your little pearl. Its the most common illness of all goldfish and its called
new tank syndrome. In red because it is highly dangerous. Very briefly, when you set up any tank you are setting up a mini eco system that establishes itself over a period of 6 weeks to 2 or 3 months. During this time you must do
daily or second daily half tank water changes. Yes it shard work.....but after that system is established, it is not hard work at all. It is agreat pleasure and sparkly crystal water and happy fish will be yours.
Right now, your water is chock full of ammonia you cannot see, possibly nitrites you cannot see and you need to get these out ASAP. Both are toxic.
Please do an immediate temperature matched (match approximately -with your finger is ok) water change of 100% and let's take it from there. Remove the fish gently using a small clean plastic bowl not a net and refill the tank.
There are a few other things you can do & we'll need to talk you through after that but this is urgent so it should be done soon. Please post back when done

I'll be here another few hours...