Cheating - advice?

Idkbro

So me and my partner have been together 2 years. We’ve been living together for over a year and about to move into a flat, with the intention of it being more permanent for a few years until it’s time for a family (way in the future).

He came home drunk at 9am after a 12 hour drinking sesh and told me he’d “got off” with someone else, which turned into a “peck” because I “don’t kiss him enough anymore”. I could have got over the kiss, but he told me he was out with his brother, but when I couldn’t get hold of him, I messaged to brother to check he was okay - he said he’d not seen my partner in months.

After hearing about the kiss and him not answering his phone all night and then lying about his brother, I looked at his phone. He’d messaged his friend that he wanted some ‘relationship advice’ saying that we’ve been going through a rough patch and he’s started to have feelings for another girl. I dug a little deeper and found what I thought was flirtatious messages between him and another female friend of his. I confronted him about it and he said he lied to his friend about having feelings for someone else and the girl he kissed was just a random girl - I am struggling to believe him. Why would you lie to a friend about having feelings for someone else and say you’ve been ‘dropping hints’ to break up with your partner?

I think he does have feelings for someone else and I feel very betrayed and hurt after all the effort I’ve been putting in to get us a better flat for our future. I still think it’s the girl he exchanged flirtatious texts with.

I don’t know what to do. We have been going through a rough patch and we haven’t been as intimate lately but it gives no reason to kiss other girls or confess to having feelings for someone else to someone else and then deny it. If he had spoke to me and told me he was feeling ‘unloved’ and started to feel things for someone else we could work through it. But the fact he’s still denying it and won’t tell me who it is - that’s the part that hurts. Now I feel paranoid and can only see the way forward would be for him to cut off contact with the girl I think it is. But even then I don’t know if I can rebuild the trust that he’s not got feelings for someone I don’t know of? Or that he won’t kiss other people when he feels ‘unloved’?

If you’ve been cheated on and tried to or got through it, how did you do it? Is it even worth it?