Maybe you aren't doing things right.

Are you using exp food ?
Are you using Gathering food ? (less fails = more exp)
Is your gear all the time up-to-date ?
Are you doing your leves, setting their levels at +3 or +4 (requieres a good gear) ?
Are you turning-in HQ items at your GC everyday ?
Do you use your FC gathering buff ?

When you have no leves left and you have to gather for good, try to farm ores, they sell the best and it's a good incentive to keep gathering.

The path to 50 can be quite boring, but 50-60 does take very little time (the leves at that level give an enormous amount of exp) and can be done in a few hours. Don't give up.