Don't let past relationships and old mistakes ruin your future. Don't let someone or something that didn't make it in your life continue to hurt you. If you do, you're still giving a portion of your life to something that no longer exists...it's like letting your happiness slip into a black hole. Learn the lesson, release the pain, and move on. Scars remind us of where we have been, not where we are headed.
Your issues have been accumulating for years and years. You have picked up 'stuff' from various sources throughout your journey, in fact, everyone that has touched your life has left their mark. They may have taught you something that will never leave you, they may have caused heartache, or they may have loved you. No matter what the reason, there is always some residue left from significant people in your life. If they hurt you, it is something that will continue to show up in future relationships until you deal with it. You don't want it to ruin every relationship from here on, so don't ignore the hurt, release it.
Learn the lesson, release the pain and move on.
Remind yourself that healing, releasing, and forgiving doesn't happen overnight so be patient with yourself. Hanging on to the past will only drag you down and you are here to enjoy your life. Just because it didn't work out with one person does NOT mean you are unlovable, quite the contrary. You have learned a few things, you know what you want now and what you need. This is about you loving yourself and choosing someone that loves you too. Don't settle.