I just found out my significant other of 3 1/2 years left me for someone else. Who else is having a shitty holiday season? What can I do to help me forget about this scumbag and restore faith in men?

Reddit, help me out. Long time lurker but first time poster.

I met my ex while we were both working abroad. When we returned home he asked me to move across country to live with him bc he wanted to spend his life with me. I believed it. Fast forward 3 years in he goes back to school to get his masters and comes home on a daily basis talking about this new girl in his class. He spends all his time with her. During a semester break, they both went out camping together while I was left uninvited bc I was working to support us. He comes home and says he's unhappy in our relationship. I confronted him and he swears there is no 3rd party involved in his decision. This happened in September. Thanksgiving break there are multiple pictures in Facebook of the two of them hugging and kissing.

So my question is what can I do to help me forget about this scumbag? And how do I restore my faith in the opposite sex?