I wouldn't dream of pretending I understand what you are going through as we all deal very differently with crisis and shocks in our life and finding out you have MS certainly falls in to these categories. I know my head was spinning with all the 'what ifs' when I was first diagnosed and its hard to know where to turn.
There is a process we all go through when diagnosed, you may have read or heard about it. It's often described as being like greiving and in many ways this is true in that when you lose someone you love you go through stages of anger, shock, resignation and hopefully finally peace and acceptance.
Same with MS, but it doesn't mean it follows a nice linear order. You may feel angry one day and fine the next, bounce through the next 5 months then without any notice you down again and depressed. Whatever you do do not feel guilty for feeling sad or upset. It is a natural reaction and just remember it will pass and sunnier days will come again. They always do.
MS may mean for most people that their dreams have to be a bit different to what was first imagined but whatever you do don' t ever give up on dreaming.
Use the MS to give you focus on what you want to do with your life but try not to dwell on it and look at the positive statistics - your young age means you are more likely to have a better prognosis and there are so many breakthroughs with MS that I am confident they will develope treatments within the next 10 years that will make MS extremely treatable. And wow, look you will still only be 24.
I hate you
PS It may be worth looking at learning some cognitive behavioral skills. I I trained as a Cognitive Behavioural Therapist a couple of years ago and it has help a HUGE amount. I would have loved to have known about it at your age. It will help not just in construtive ways to deal with MS but in many many areas of your life. Have a look at these links for details
http://www.academyofct.org/Info/Guide.a ... =gimqmogus