weight gain/medication

I am 5 years out and lost 100 pounds got down to 137 and kept it off for a year and a half but I started having some medical issues such as chronic migraines, chronic dizziness, vision issues, hearing loss, found holes in my skull and am needing brain surgery but I have been put on so many medications and I have terrible nausea I'm in the bed a lot due to the migraines and dizziness so I don't eat anything but crackers but do sip on water..i'm sooo wanting to lose some of this weight

first you need to get healthy , losing weight when you very sick is not a good idea

 follow or doctors directions now and lose the weight latter after you health problems are solved 

Does your neurosurgeon have a nutritionist on staff that you can talk with?