I cannot consume dates, figs and raisins due to heat in the body as I have pitta dosha. What alternative I can use?

In this case, you can have all these dried fruits soaked. Soak dates, figs or raisins in water for 2-3 hours. Doing so reduces the heat present in the dried fruit. 

Apart from this, there are other natural sweeteners you can opt for, such as : 

• Jaggery (in the form of powder or liquid)
• Fresh stevia leaves or stevia leaf powder