How to repent if i lied against myself to my own family while they believed in me instead i broke their trust and promises?Is there any kaffarah for this?And is repenting to Allah(swt) enough or i have to expose my lies?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Repentance from lying – like repentance from any other sins – is by giving up lying, regretting it, and resolving not to return to it in the future. Whoever resolves to give up the sin, quits it, and regrets having committed it, while his repentance is for the Sake of Allah – the Most High – then he has fulfilled the pillars of repentance.

The Prophet said: “Whoever repents before the sun rises from the west, then Allah will accept his repentance.” [Muslim and Ahmad]

There is no financial expiation for repentance from lying.

It is not required for repentance to be valid that a person confesses to the person whom he lied to. The basic principle is that the person who has committed a sin should conceal his sin and not expose himself, unless lying resulted in the loss of a person’s right, such as the loss of wealth, or accusing him of what he is innocent of, or lying about others, such as giving false testimony, and so forth. For the repentance to be complete [in this case], one should give back the right to its owner, and testify that he lied in giving false testimony.

Allah Knows best.