What should I do if people think I am lying?

If people think you are lying and you are not. Then be honest and tell them how you are telling the truth. Explaining a situation they assumed can be helpful if it causes any issues

Calmly explain your logic as to why they think you are lying. Rationalize within your own life why other may be thinking this way and be confident in your own decisions.

Tell the truth. Let them know that you are telling the truth. If others don't believe you the most important thing is to believe yourself. You know that you are telling the truth even if others don't and that can be really hard.

Explain why they should believe you. Also, do not exaggerate. It will make it easier to believe you.

You should not get agitated and explain that you aren't lying, and if they do not believe it, then so be it. You don't need to prove yourself to anybody.

Prove to them that you're not, and if you can't prove it and you have no reason to lie, explain to them that you have no reason to lie, and if they think you do, ask them what that would be. The big thing here is explaining yourself. If you explain yourself and yet they still accuse you of lying, especially if they're your friends, they aren't worth your time.

Reasure them that what i am telling them is the truth. Unless they have any other reason too believe i am lying theres no reason too carry on the discussion. If they do not stop i shall walk away

If people think you're lying, I guess the best thing to do is show evidence that you're not. And if there is no evidence or they simply aren't convinced, then maybe it's best to let them be. A lot of times people judge us and it's not even because of us or actions we did, sometimes it's about themselves. So I guess depending on how important it is for you to prove them you're not lying, I guess if it's not too relevant, maybe you could just ignore them.

Everyone is entitled to their own perspectives and opinions, so long as it is not affecting other people's lives. You can always start by confronting the person and you talk about the facts that concerns the situation. If you have explained everything and they are not convinced, there is nothing more that you can do, you don't have to prove yourself! you did your part and your true friends and families know what is true, cause true people who really knew you believe in you. :)

Be confident about yourself. Self doubt is sometimes the cause for people thinking like this. The more confident you become the problem will go on becoming smaller and smaller.