I'm glad to hear things are going well. I left for about 11 weeks on FMLA leave, practically pushed out the door by my supervisor with her saying how good it would be for me. My primary care doctor actually helped me a lot. But when I returned to work I got mixed reaction and decided to just come out with it whenever asked - I have epilepsy and was on leave to get the seizures under control with medication and alternative treatments.
Some people reacted well others looked at me like I was mentally challenged or had three heads. Now my supervisor is making my life miserable, she met with me less than two weeks after my return for my annual evaluation and tanked it and cited "personal problems" in it, she raised the expectations for my job performance to such an unreasonable point that others on campus have suggestd I seek either legal counsel or go to HR. She told me she has to "protect the college" - from what, my seizures? I have had seizures at work and had to be removed by ambulance, but that was before I, or anyone else, really knew what was going on. Now we know. No EMTs unless the seizure lasts 5 minutes or longer or I break a bone.
There is discrimination, but I can't prove it yet, though I'm compiling evidence. It is not helping the stress situation. I also feel that exhaustion when I get home. She will point out every mistake and with the volume of work I'm doing I might type there instead of their sometimes. So I've started pointing out her mistakes as well, which hasn't helped. I want to wear a shirt that says, I have epilepsy, what's your excuse? But that sort of feeds into her hard on for me and isn't exactly politically correct.
I hope your coworkers and supervisors are supportive. It means the world to me when someone just says, hey how's it going? You doing ok? Because if I'd left on FMLA with uncontrolled blood pressure or hypoglycemia, this wouldn't be happening.
Some things I've done since returning from FMLA... I try to get some extra sleep, I take little breaks where I can at work just to get up and walk down the hallway, I've started listening to music when I don't need to concentrate too hard, if I have time I will go online and read some jokes - I especially like one liners because I can read like 10 of them in 2 minutes and get some good laughs which helps. If I have time at lunch, I try to take at least a 20 minute walk around the block and have lunch with a coworker to chat about non work things. I often read and check in on here - that's a big stress reliever.

I just find the less stress the less nausea, though I have no experience with Keppra. Also, I get nausea with migraines and find both ginger capsules and mint tic tacs or gum will sometimes help. I also take B12 sublingual tablets along with vitamin D and fish oil and magnesium at night. And a multivitamin. All of that was approved by both my primary care doc and neuro. I was vitamin D and B12 deficient but not any more. I think the routine takes time and the energy gets a little better. I also often sit on a heating pad in the evenings and try to walk a few nights a week with my daughter.
Ah working with seizures.... It's an adventure! I'm wishing you the very best!