I think work on urself and leaving them behind is good option..

Your question itself has the answer..

Stop playing a victim card...🤌

Or you could just whine about it on the internet.

Since you didn't leave it behind,
whining about it on the internet is definitely the correct call, cry baby

Ignore them.

There is only one way.
Cheat the cheater of your companionship.

It really depends on what they were caught
cheating at.

For example: It's perfectly acceptable to
break the fingers of a card cheat.

Stop inviting them to card-playing and board games. "No more Scrabble and Monopoly for YOU!"

Move on !

embrace with her/his neck tightly.

The murder mystery

that's an end too it.

If you have been in what you thought and agreed was a serious monogamous relationship for only a few months before they cheated on you, then yes, I agree leaving them behind is the best option. If you have been in the relationship for a year or more, then maybe you could talk things over with them, to reconcile, unless of course you are unable to forgive them.

Just move on and cut your losses.

Roman,
Cheating breaks trust and puts a relationship in turmoil. It usually involves lying to someone you should be trusting.
Don't Do It.

If you were wrong about the choice you made, break it off BEFORE you cheat but break it off gently and respectfully.

If you still care about her and how she feels, Don't Do It.

If you are feeling sexually deprived, talk honestly and intimately with her about it before you roam.

Trying to justify cheating on a dating site is wrong in so many ways.

If you have been cheated on, look at your relationship from her point of view and see if you can honestly say to yourself..."I deserved it".
Then have some honest communication with her (remembering to let her talk as well) to see if there is anything worth saving.

If you are met with hostility or lies you may want to move on and call it a learning experience. But...If you do break it off, break it off completely.

Once a liar, always a liar.
Once a cheater, the trust is broken even if it never happens again.

You can work on the trust issues but if she cheated, she has already shown you she is not trustworthy.

Without two-way honest communication you are wasting your time.

Take back the power over you that you have surrendered to her under false pretenses.