How can i let it end

M)23 (f)21

I just have one question guys , i cant let her go , she's always going away and coming back after a long period thats been happening for 5 years now , i truly love her and thats why i keep geeting back with her because i cant get her out of my head , and she did that again for the 5th time , its always me who was trying she's always leave because she overthinking about herself and she isn't the good one for me but, i want to ler go but its like my heart cant process cant even believe if thats an option and i can do it , if someone been through this please any advice would be appreciated , i blocked her i did everything but still fant stop overthinking in everything literally , but i am the same dude everytime i want it over

How can i do it ??