Jealous best friend issues?

Has anyone had any issues with their friends being over-jealous and causing issues in your relationship??

My “friend” and I have been friends for 10 years. Through those 10 years, I never had many relationships. None that were serious anyways. My fiancé and I have been together 2 years and we are very much in love. My “friend” seems to cause issues in our relationship. She tells me I’m too stuck up my fiancé’s ass 24/7. (We both work and I’m a full time college student getting my associates degree) we only see each other evenings and occasional days off, so the time we have together is important to me. She claims I never make time for her anymore. Yet I invite her to come to my house and go out to lunch/dinner. She always declines. She only seems to want to hangout on her time only and it never works for me. I explained to her that I have my own life now and that I’m sorry for not being available all the time like I was at one point in our friendship. She’s gone as far as trying to feed me bullshit about my fiancé. Saying “I know some things about him” yet she refuses to tell me what those things are. They are most likely bullshit to begin with because my fiancé has been open and honest about everything he’s ever done in his life. She started blowing my phone up all the time, even while I was in class. I explained to her that I’m busy and can’t answer her all the time. She wasn’t too happy about it. So I told her with everything going on in my life, I felt it was best to put our friendship on hold until she can understand that I am trying to better my life. She was seriously SO pissed. Now she’s spreading rumors about my fiancé, that he beats me and is mean to me. She even told my family that we are trying to have a baby when it was supposed to be a surprise. It’s really hurt me and made me upset that she’s telling my family and other friends my business just because she’s unhappy. She has openly admitted that she was jealous of my fiancé because he can make me happier than she can. (Creepy?) she’s not happy in her marriage so I feel like maybe she’s trying to ruin my relationship so I’ll come back to her as her friend? Has anyone else had this happen to them? What should I do?