Thanks for the question and put your worries aside.
Think of Mary Magdalene and how tainted her past was.
- Can you imagine how easy it would be for her to think of her unworthiness to hang out amongst Jesus' inner circle of friends and companions?
- How did she adjust?
- How did she break from her past?
Part of it is knowing how deeply-loving her Savior is and that He doesn't want her to carry that burden around — when He forgives, He really does forgive. She saw how real that forgiveness was up close and personal — let's take our cue from her. It is very easy for us to look at our current state through the lens of our past sins and failures, but God doesn't want us living in that mental space. He wants us to move on and to start anew. If you fail 1,000 times you must start anew 1,000 times. The Christian life is a marathon and you may stumble along the way, but our eyes must be set on (the goal) the finish line.
Put your Scapular on each day (you probably take it off to shower anyway) and give it a kiss and say to the Lord:
|"Thank you for your Love, thank you for making me anew, and I am yours, let this Scapular be a sign of my new life in you".
It is not about your past, it is about right now, and you are in no way disqualified for the promise. Only satan would want you to think otherwise.
We Christians are a collection of sinners being transformed into the likeness of Our Lord, adopted children becoming more like our parents, all the time. And I say parents because we have a mother in Mary, who shows perfectly what it means to be fully human: a child of God who has become a magnifying lens of God's grace. Let Jesus and Mary change you and don't be afraid to go to them when you stumble. Sometimes you need a mom and other times a big brother, a dad, and always a friend.
In faith you have all of that, so now use it and live in it.