Toxic BFF

Tehya

So my best friend of 7 years recently started dating my ex bf that she KNEW I still had feelings for without asking me or anything ( she had broke up with her bf a month before this) she’s really rude to me sometimes and I KNOW she talks shit about me behind my back. I don’t know if I should forgive her or just throw away our 7 years of friendship. What do I do???? Please help