Do you do a lot of instances? Enchanting does indeed come in handy for those bind on pickup items that are of no use. Other party members will also appreciate it if you are willing to DE any items they win that they don’t need either. However, if you don’t do a lot of instance runs then you may find that you don’t use your disenchanting skill as often as you might think.
But should you decide to pursue the enchanting profession you have a good source of income to support it from your herbalism. Your also at a good level to solo some of the lower end instances to support the early stages of enchanting.
Alchemy is a great profession if you take full advantage of it. For example, I have a friend who plays a rogue with herbalism/alchemy. His character stuffs her face with potions all the time, boosting her performance very noticeably. I, on the other hand, have herbalism/alchemy on my warlock and I have a hard time remembering to use a heal potion if I’m about to die, much less using potions to buff my performance. So alchemy is great for him but not so much so for me.
If you don’t enjoy alchemy then switching to something like enchanting might be a good change of pace. At worst you could always drop enchanting and take alchemy up again. All it would cost you is time and money.