MRI shows bulging discs & early degeneration. Unable to get out of bed for a week, now suffering from migraine & nausea. Could these be looking linked?

Back migraine. The findings on the MRI are very unlikely related to the migraine and nausea. You are only 31yrs the early degeneration is a process of ageing. As long as the bulging disc are not causing stenosis or compression treatment should be PT. The migraine with the nausea is treated differently.
Pain in the neck. Or abnormalities of the spine, such as you have, can cause pain and tension in the neck, which in turn can cause primary headache or migraine. See a headache specialist for proper diagnosis and management.