Congratulations on the trip plan! It is said that travelling is a state of mind and I believe that you have the right state of mind for this endeavour. Being young surely helps, as well!
I too, although not particularly young, enjoy "rough travel" and as this is an "ADVENTURE cycling" website, feel that your trip surely counts as an adventure!
Hmmm, going to be tough to maintain a vegan diet while on the road. It's that whole protein thing...
Well, pack soft coolers and load up on the tofu. If you're finding that your performance is suffering from an incomplete vegan diet, don't sweat it, the trip is more impotant than the food you are eating. If you have to, canned tuna and eggs are pretty cheap to buy.
When you finish the trip, go back a vegan diet, don't feel guilty about the diet change and LOVE how you are going to be changed by this trip and the great stories that you will be telling friends and loved ones, for a long, long time.
Closer to Free