This is NOT the end of the world for you, now you have a diagnosis, now you know what you are facing, now you simply need the correct arsenal of tools to deal with the problem. I am curious as to what the results of your overnight PSG revealed, sometimes treatments for hypersomnia lie in treating the night time sleep.
It is my opinion that it is as important now to have goals even more so than prior to your diagnosis I think that your plans for the future should not change. You will need to make some adjustments but placing your life on hold is not the answer.
There are many treatments available for this problem however, none are as important, or effective as your own attitude toward the problem
I certainly wish you all the best