missclairol,
Welcome to the forum.
Yes, try the prednisone. For some it works great, for others not so much.
They didn't give you any other meds? No mesalamines? No rectal meds?
I think it's not right for the doc to scare you by telling you that you'll need surgery. That's a red flag to me, that he may not be the right doctor. He should be giving you lots of other options IMO before telling you about surgery.
But there are many things IMO which you should be doing in tandem with the prednisone to calm things down, so that when you are tapering entirely, you'll be at a good point.
To me, those would be a combination of diet modification, certain supplements: probiotics, vitamin d3 levels checked, slippery elm powder, l-glutamine, and perhaps you can look into LDN, low dose naltrexone too.
There are things IMO that you can control, which will have a direct impact on your disease, the symptoms you experience and their severity.
I was able to control my UC into remission through various supplements, probiotics, diet modification, and LDN , low dose naltrexone.
For more info on the protocol which has put me into remission, please go to this link: https://www.healingwell.com/community/default.aspx?f=38&m=1666318 , and look at the 11th post.
I hope you feel better and let us know how we can help you.