I had alchemy and herbalism until 70 and bit longer. Then I dropped herbalism for tailoring. I farmed all the mats above silk myself (and scryers rep to exalted along) and I got from 1-375 in 2 weeks.
I made all I wanted, FSW, spellstrike, battlecast and so on, I farmed and made almost all the mats with my 2 professions.
Right now I am only making earthstorm diamonds for sale and 20 slot bags for my hunter alt, occasionally I make piece of shadowcloth or spellcloth for sale if I get the mats while farming something else.
I am sorry for my herbalism every time I see a plant I cant pick anymore. But then I am sorry when I see node I cant mine too, or some corpse I cant skin.
I made enough gold to buy epic flyer on my main and powerlevel JC on my alt, and I am still making it.
Once you get to 70 there are lot of ways to make gold and you dont really need gathering profession. Until then you are better off if you stick with what you have.