hey Jayanth,
I can't argue about the opinion your surgeons have but all I can add is that I know that colostomy might sound scary but what if it brings you a quality of life? I got my ileostomy at the age of 14, I have 26 now. I was scared at first that people would react (intimacy talking), some have, but it was a minority. Most people understand and does not care and Im not just talking about the "if they love you they will love you the way you are". I'm talking about people I met and to whom I had to tell on the spot because hey, well that was it lol, and it was fine. It takes a time of adaptation, that's a fact, but a few months in and it is a whole new world that is there. If that's even an option at some point, please consider it, if it is a way that could help you have a better life quality at the end.
And yes, Infliximab could help long term. Normally it takes a bit of time before reaching it's maximal effect but it is possible that you don't respond to anti-TNF too...
I hope you find some relief soon, and don't give up, it's one down to go trough but it's always darkest before the dawn.