Should i keep this Friendship?

ok so heres the thing..me and a friend have been on n off bffs since like 3 years ago..like we always end it because some stupid things but thing no long afterwards we become friends once again..like im so tired of it right now and it hurts everytime we end our friendship..sheve backstabbed, said trash about me, and it seems she cant be trusted anymore but than again im not sure..she denies all of it saying shes not talking trash about me but everyone can tell she is..and shes asks others advice if she shall stay my friend or not when we arent even fighting so idk….so like what should i do? should i end this friendship once and for all?