Reasonable Accommodation Cancelled and Replaced

My reasonable accommodation which allowed for telework has been cancelled and replaced with one requiring me to be in the office. My situational telework accommodation has been changed to the option of unscheduled leave usage, LWOP, and a more flexible schedule for start and stop times. Additionally they've moved me to a dark room to help with my condition, chronic migraine with visual aura.

I know it makes me seem like a baby with "headaches", but my migraines bring extreme pain, light sensitivity, visual impairment, nausea and vomiting for 1-3 days after the initial trigger, and essentially makes my job no longer a livable option for me. I've been taking sick leave every week trying to find a way to make this work, and it's affecting my time with my family as well. The same old fluorescent lighting with low flicker rate (migraine cause) are in the hallways, bathrooms, break rooms, etc. Even in the dark room, the migraine is triggered by the end of the day for me with 100% certainty. I'm wearing filtered glasses and taking preventative medication, and nothing is working.

My boss' boss told me telework is no longer considered an accommodation in the agency and that there's nothing he can do.

Has anyone dealt with something similar? Any advice?