Cheated on for the past two years

I don’t even know where to start - I am completely broken and I guess I’m turning to this page because I’d like to hope that I can maybe talk to others who understand. I’ve been with my boyfriend for just under 4 years and for the past 2 years he has been having an affair. I am broken. We have a home together, a dog and I am just broken and feel like how do people get through these situations and also how do people do this and cause so much pain? Please be kind, my heart is broken right now xx

EDIT: this community never fails. All of your comments and words are so kind, uplifting and what I need right now. I have received hundreds of message of support and of confirmation that this guy is a serial cheater and a dating sight scammer who I have been gaslit and manipulated by for years. Safe to say I can publicly promise I will absolutely not be taking this absolute fool back xxxx so much love to you all, you are all amazing xx