OP, I know you previously said that in terms of disability services, all you qualify for is to be "shadowed" while at work. I apologize if I have my facts wrong or if this is a stupid idea because I am not well-versed in this, but have you considered going to Social Security/Disability and speaking with a vocational rehabilitation counselor? That is a division within social security/disability in which their whole purpose is to help people with disabilities and/or medical limitations find work that fits with their skills/education/interests AND in which the employer works with the agency to accommodate the needs of the employee. Employers who participate in the program, to my understanding, receive tax benefits and other incentives as well as assistance to accommodate the employee. I apologize if you've already tried this, but if you haven't, I would urge you to call and make an appointment with your local office.
I hope things work out for you and wish you great success.
ETA: Also, who knows? Since you're already employed, maybe there's a chance they can contact your employer and intervene for you and help work out this issue? I can't guarantee it, but maybe there's something they can do. And if not, maybe they can help place you in another job where the employer is prepared/able to work with you around your medical appointments. It sounds like you do want to work and be gainfully employed, which is wonderful, especially considering your medical limitations. This government agency's whole purpose is to ensure that individuals such as yourself are able to work and NOT have to leave work to collect disability. AND if you do run into a problem such as you're having while working at a company with whom they have have placed you, you call them, and their job is to FIX IT for you.