I had botox injection on both palms, but it hasn't worked. Should I go for botox again or opt for something else?

Botox is a great way to temporarily reduce hyperhidrosis, it would be helpful knowing how many units were applied to each palm, I suggest you follow up with your provider to discuss the amount that was injected 

The number 1 reason for Botox not working is that you didn't receive enough of it. Continue following up with your injector so that you can determine what the right dosing is for you. Don't give up hope as I have found Botox to be a very effective treatment for excessive sweating. 

I would discuss your lack of treatment response with your MD to see if something simple can be done, like a discounted touch-up treatment.  Another option is treatment with iontophoresis.  Check for a local office that carries the treatment and can provide support, and then the MD can prescribe the home-use Fischer Galvanic device which is often paid by insurance.