One of my closest friends recently has become closer with someone else. She says she still loves me and that were not drifting apart - but I cant help but assume the worst. I've had a huge problem with jealousy in the past and every year it gets a little easier but I don't know what the correct way to deal with these emotions are? My natural instinct is to repeatedly confront her until she gives me a clear answer and starts spending more time with me (which of course, I will not do because that's extremely unfair to her.) Once I tell myself that I cannot behave like a child, and I must not inflict my toxic feelings onto her - I want to hide away. I have this feeling like I want to cut her off to protect myself from feeling like this so I can focus on 'getting over the relationship' as it were. I know this is not good either as I love her to pieces and I would regret that massively. Furthermore, I don't genuinely believe that she does not like me anymore so I don't know why I feel this way. Whenever I see them together I want to cry because I feel like I should be doing a better job than this 'new friend.' I should be just as funny, kind and friendly. "If I did better, she would want to hang out with me more" I think to myself. But there's no room for me to do anything. I don't know how to explain it, but it sucks because she's honestly the best friend I've ever had, she deserves someone who can manage their emotions properly. Thank you.

TLDR: How to cope with my feelings of jealousy around my friend in order to keep our friendship and protect myself emotionally at the same time?