Steroids can knock you for a loop emotionally. If this is your first experience with them it's such a slap. It really rips the rug out from under you sometimes. I did 1 round of steroids with my first flare and vowed to never take them again. Not only did I not sleep I was a total grouch for the entire cycle. Up and down emotionally. It was really just too much for me to handle along with the flare, too.
Here's a link to a website called Multiple Sclerosis Sucks....
http://multiplesclerosissucks.com/. It approaches MS with humor and it's a great site to direct those in your life to (like your BF) for information that won't scare them half to death.
I hope you feel better.