My girlfriend cheated on me and it has ruined love for me.

I am a 19 (almost 20)-year-old man, and I found out 8 months ago that my girlfriend is cheating on me with another guy. My girlfriend (or ex) was very busy with her campus organization, and ever since I found out, she was disrespectful towards me, rarely responding to my messages. Her friend messaged me, saying that my girlfriend is cheating on me with another guy, and they even sent me a photo of my girlfriend with the other guy together.

My heart was shattered. I tried my best for her. We were in a relationship for 18 months (last 6 LDR), and I loved her so much that it's ruined me.

I don't know if I ever want to find another relationship again after seeing this stuff happen all the time. I had my childhood be exposed to infidelity and I always hoped that this would never happen to me, and sadly it has. I just really wish I could find a decent woman in person and even online if I have to, to date and maybe marry that is loyal. Just seems like 1 good person in a million in this generation based on social media atp. How do I get over this hump and find someone meaningful for me whether that is irl or online without this constant fear of it happening again?