I'm so sorry you've gotten confirmation of what you've likely suspected all along. And it's tough having to hear that sort of thing right now, when everyone around you is celebrating the holidays, too.
But it's NOT the end of the world, or the end of life as you know it! Lots of people continue in their careers, have babies, do all of that, while still dealing with MS (or other chronic illnesses).
It does sound like you have relapsing-remitting MS. Sometimes folks newly diagnosed will experience a series of exacerbations, and then it'll level off and not be so troublesome. And these days, with the new meds, there is every hope that once you get on one of them (and I see you're choosing Copaxone), the progression will be dramatically slowed, and you'll do well.
I've never done the intravenous (IV) treatment, so can't offer any insights there. I hope it goes well for you.
You have every right to be scared, by the way -- but I'd really urge you to tell at least some of your family and/or close friends. You might be pleasantly surprised at how supportive they might be.
And once the shock wears off, don't hesitate to be back with questions as you start down this journey. Take care.