Your feelings are a good indicator of your state of well-being. Listen to them, they are serving you well.
If we feel emotional pain, we think the source of the pain is someone elses words or actions. Nope. It´s not. It is your Soul, saying you believe something that is not true and not grounded in love.
You might say: “Yes this cheatin´idiot didn´t express truth or love, when betraying me, therefore I feel pain.” Yes and no. It´s high likely that his actions haven´t been grounded in truth and love, but this pain is not about him. It is about you. What are your assumptions in this case?
“He never loved me. I´m unworthy.” Lie. Ouch.
“He chose her, cause she´s younger. I´m old and ugly.” Lie. Ouch.
“Why does that always happen to me? I must be stupid to fall in love with such a fraud.” Lie. Ouch.
“I´ve wasted the last 5 years, being with him. Should have known better.” Lie. Ouch.
See, to your Soul you are love. Your Soul knows no age, no time and no judgement about outer attributes. So it is your mind, telling untruth, that is causing the pain. You, handing your power to someone else, that is what is not truth and not love. That is painful.
And of course I would agree, it´s high like likely that your mates actions are grounded in non-love. But the only one that can really harm you, is you giving away your own power to a cheating guy and false assumptions.
Someone that loves and respects you wouldn´t hurt you with intend, here I would agree. But that goes home with him. The only one you are responsible for, is you. He, his reasons and state of (un)consciousness is none of your business or influence. Your past is also not to change, and regret is leading nowhere and therefore not an option. But now, in this moment, you are deciding about your future.
It´s no more important if he loves you, but if you love yourself, you´ll make sure to feel good about yourself. Give yourself what he didn´t. Love, honour and respect yourself fully.
If that includes to get rid of his cheatin´ass, than do that. If you wanna Keep him, because of whatever reasons, than do that. There are no rules, but what feels good for you. Whatever you choose, decide out of love for yourself.
Cause that will feel good. It´ll give you a feeling of strenght and selfworth. Ain´t that a good idea, someone doing you wrong and you are becoming stronger than before? That´s what it feels like, when you are in charge of your own life, cause that is what you came for.
Shine your light!