I know how you are feeling but hopefully once they get your meds sorted out now that the disease has progressed you will start to feel better and have a different outlook.
You are right this is a debilitating disease, I was diagnosed back in 2001 and still fully haven't accepted it, I still get very teary when I am unwell and think why me? but you really have to try and look on the positive side. My brother eventually had surgery for UC and although at the time it was very traumatic (I didn't have UC then) he now lives a med free life and is never ill and I remember him saying to me that at least with this disease they can take the affected organ (colon) out and you can live a pretty normal life but with any other diseases e.g liver, lung, heart, kidney you can't live without the organ so in some respects compared to people living with these diseases we are lucky. Although saying that I know when you are unwell it's very hard to think like that.
I did change my job, I used to work in the financial services where we under pressure to make certain sales and targets and when you are unwell most of the day and trying to deal with that it's very hard. I quit that and now work in the evenings (which is when I feel most well) and it has worked out a lot better. Also it is a very stress free job that I have, just the way I like it.
Best wishes to you and I hope you turn the corner soon and start to feel better.