Can we put vaseline on our lips when fasting; or no my lips are hurting a lot?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Applying moisturizing cream on lips is permissible as long as one does not swallow it. If one swallows something from it knowingly and intentionally his fast becomes void and he has to make it up later.
Likewise, using other creams for skin care is also permissible but one should be cautious and not let anything enter inside the throat from his nose or eyes.
Allah knows best.