You’re wife has been through a great deal with her MM history. Was she able to use her own cells with her Stem Cell Transplant?

I don’t know very much about Revlimid as I’ve not taken it personally. But some of the symptoms your wife is experiencing do seem to be on the list of common side effects of the medication.
However, I do know it’s possible to develop new reactions to a medication even after being on it for 8 years without issue. This can happen because metabolism decreases over time, meaning your body doesn’t get rid of it as fast, leaving higher concentrations of drug in the bloodstream, which increases the likelihood of developing side effects.

Has your wife been in contact with her hematologist/oncologist? What do they have to say about her side effects?