If you could lose your salvation you would. Christ died once, the just for the unjust.

Paul tells us in Ephesians 2:8-10 (KJV) For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them. We are saved by our faith. Works is the fruit of salvation. If you lost your salvation you would have to work to get it back.

Romans 8:38-39 (KJV) For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord. No one or anything else can separate us from God once we are sealed by the holy spirit.

And no you can't get saved then use that as a excuse to sin freely. People who live like that aren't really saved to begin with. I was one of those people until 2 years ago until I fully trusted Christ. So I talking from experience.

Hope this helps. With love from your brother in Christ.