I can't do onions either! Though I can tolerate a clove of garlic here and there.
I find some vege juices a bit heavy going by themselves. (Except carrot but I limit that due to its Sugar content - I have a candida problem).
Celery and cabbage I find ok on their own but spinach and cucumber I need to drink mixed with something like a bit of green apple to make it more palatable.
My tastes haven't really changed but I persevere with different veges, find ways to make then "work" (ginger is good too!) because they contain so many good minerals.