I have learnt my lesson I should always tell the truth. But now my boyfriend has left me and said is done he won't take me back cause he can't trust me. I promise I will never lie to him again I shouldve told him I was afraid I would lose him if I told him the truth. Now I know the truth is the only way. How can I get him to believe he can trust me?

You can't. Trust is earned, once lost is near impossible to earn again.

Learn your lesson and move on. Don't do the same thing in your next relationship.

From my point of view Trust is very important in any rlationship and if it is broken the other side should give a chance to prove them again.. If he is not giving the chance I hope he don't love you.. Or else he should have understood you that why you told lie.. Nothing is important in love if both love each other.. and if the person is coming back after doing the mistake he should understand you.. Anyway you just leave it to him.. You told the truth and you have did right thing from your side.. Now the ball is in his court.. Leave it to time and destiny but on the same hand don't wait and beg like a fool.. Leave everything to time and destiny.. All the best

You can't. Let this be a part of the lesson you have learned. Saying that you have means nothing, and a promise from a liar also means nothing, leave him alone, you have disappointed him and he has made the RIGHT choice for leaving you because you have lied to him, let him live his life and you go do yours elsewhere. You cannot control the mind of someone else and there is no point to continue a relationship where trust doesn't exists, which is what he has noticed.

Good Luck,
Javi

Unless he is willing to give you another chance, there is nothing you can do but move on and do better next time.

There is no way to make him find trust again, Depending on what the lie was, it could be a combination of what you did and the fact you lied. Plus who knows about other unknown issues going on also.

Unless he is willing to try, you just move on