I deal with the same awful cycle. The more I work, the faster my UC gets out of control. The less I work, the less I am able to afford healthcare. It's terrible.
When I wasn't able to afford medication in the US, I ordered from Canada. It is much less expensive there.
Canasa has a patient assistance program that brings one box a month to $20. It isn't as effective for extensive inflammation but if you're dealing with rectal inflammation, it may be helpful. There is a link to the program in the resources thread at the top of the forum.