Should I mend our friendship or walk away?

There is this girl that I known for 3 years and I been having feelings for her since the day I met her which is sort of sad. I was the first person to ever like her and I still haven't gotten over her after 3 years. Our friendship has always been rocky because I would get jealous everytime I see her with another guy. We thought we fixed our friendship recently because we started talking to each other again after a year of not talking to each other and seeing each other. So I asked her out and she said NO. I broke down basically because she led me on for a good 2 months before rejecting me. I told her that it's alright to just cut ties with each other and we both said it's better that way. I tried to cut ties with her before but she came back into my life. I know I'm a pussy and **** cause I can't get over her. Was it right for me to just cut ties with her like that even after a long friendship? Has this happened to anyone else before and what happened?