People who stayed after being cheated on, any advice?

I’m trying not to put my sadness and anger on here and be as concrete as possible.

My boyfriend and I are in a LDR due to him being in the army. He had a female best friend who was close to him. She was married back then and has a child with that man (army buddy of my bf).

Apparently he introduced them but the story told by her was more of an accidental meet up.

Long story short he had an emotional affair with this woman.

I found out because she would be condescending to me after almost a year of dating “her man” and would act extremely possessive all of a sudden. It raised suspicious and everything came to light.

This guy is my best friend. The bond we have is so strange and unique and I do love him. All of this is still causing me so much pain and it hurts talking to him. It’s been 3 months since that happened and I feel so hurt.

He cut contact with her and the ex husband and is trying to win my trust again but I’m unsure to continue this relationship.

Is there any way to work through this?