Has anyone ever experienced extreme jealousy over ONE girl?

And find yourself constantly comparing her. CONSTANTLY.

It’s my boyfriends close friend (she IS married and seems happy) her husband IS ok with her having close guy friends…

But I have heard my boyfriend talk about her the past 3 years and to ME I swear he is secretly longing for her and it makes me so uncomfortable and I try to be supportive and be okay with it because I never want to be “that” girl

But my mental health is taking a toll.

How do I get passed this? All I do is think about her and compare myself to her because she is literally perfect in every way… I know my boyfriend sees it. It’s embarrassing not being confident enough to just let it be and be okay..