Then why did Jesus have to die?
Jesus didn't HAVE to die, He CHOOSE to die.
"Therefore doth my Father love me, because I lay down my life, that I might take it again. No man taketh it from me, but I lay it down of myself. I have power to lay it down, and I have power to take it again. This commandment have I received of my Father". John 10:17-18
if your salvation is up to you, why did Jesus have to die?
My salvation depends on my response to the Gift Christ has presented to me as a result of His death. I can choose to not believe, and be condemned, or I can choose to believe, and have life. Salvation is not earned by me - but I can refuse to accept the gift.
"For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil". John 3:17-19
Regards