When your self-esteem is eroded, you may question your own judgment. You may question if you would even know a good partner if one showed up. You may feel like you cannot turn down anyone who expresses interest because your instincts may be faulty. Maybe you have withdrawn completely from trying new relationships because you feel they are just doomed to fail anyway. Self-esteem issues can also show up as insecurity or trust concerns. If you are constantly looking for reassurance of your sweetie's affections or need to know where he is 24/7, there may be an underlying esteem issue. These are just some of the ways it can manifest.
So what to do? Begin by realizing that everyone—you included—is a work in progress. We are all perfect in our imperfection. We are all human and we all make mistakes. Each of us has gifts and qualities to share with the world. Some may be unique to you, others just unique in how you express them. Spend some time thinking about your positive traits and write them down. Ask your friends and family what they love about you. What makes you a good friend, sister, mother, daughter, co-worker, or boss? Embrace these things and give yourself a pat on the back, or as a colleague says, "A pat on the heart."
Build in a failsafe mechanism for yourself by determining your boundaries and values. Boundaries are the determination of what behaviors or actions are okay with you and which ones are not. They are that perimeter that when someone pushes beyond it makes you uncomfortable. Knowing what yours are solidifies your sense of self. Values are the things that are important to you such as family or commitment. Knowing these gives you standards to operate from whenever you meet someone. You can compare them against your list of values and know whether or not they are a good fit. Your values will also help you to determine your boundaries.
Being aware of these "demons" at work and implementing the suggestions to throw them out will have you dating in a whole new light. It will be easier to attract the relationship that is perfect for you.