I can't help you with the long term question AMN, sorry.

I tried the "interferons" back in the late 80's as part of a drug trial here in OZ.
I suffered rather nasty migraines for the first time in my life, while I was on the trial, so that put an end to me going on those.

When I went to Copaxone in 2001, I had different... and even nastier side effects. I ended up taking fits and being admitted to hospital.

Needless to say I am now drug free, and have been since the Copaxone incident.

Big hugs coming your way AMN, and hope you find peace of mind soon.