Hello! Please remember that my response is for information only, we are not establishing a therapeutic relationship.
I hope that I can be of some help to you.
Being told that you are "less than desirable," sounds abusive to me. Can you fill me in a little on who told you that and what that's about.
Are you a person of faith? If so, which one? I can speak about sex from a faith based position.
Please follow up and I will use your feedback to form my answer to you. I see you are offline, I will check in the morning for your response.
Hello again --
I see two issues going here, and neither of them are consistent with Christian theology.
#1 --As I've stated before, the way these women have treated you is abuse. To be told that you are not beautiful, "might" become acceptable, or be able to be loved is horrific, and in complete opposition to the entire message of the New Testament. The Old Testament also delineates how much God loves each of us, with the most poignant example being Psalm 139: For you created my inmost being; you knit me together in my mother's womb. "14 I praise you because I am fearfully and wonderfully made;your works are wonderful, I know that full well.15 My frame was not hidden from you....."
Hurting a child abhorrent to God (Matthew 18:6)
#2 Sex is an area where many Christians seem to take the prohibition against pre-marital sex and distort it to mean that all sexuality outside of the context of a marriage relationship is wrong. This does not make any logical sense, we are created by God as sexual beings, and this nature cannot be turned "off" (as some seem to state) depending if we are not married.
Therefore, "craving sex" as a 21 year old woman is completely normal.
Your question --about what to do? Here are my ideas:
1. Get some therapy. The messages about who you are as a child are extremely powerful and are most likely integrated deep into your identity. It takes some work to eradicate the effect of these messages.
2. If you have remained a Christian, you need to explore what God really says --not an interpretation from one group. Here's some resources for you:
Some interesting articles on God's design for sex:
On this site you can read about why that there is NO Biblical evidence that masturbation is a sin --and masturbation relieves a TON of sexual tension.
You might also find these books by Henry Cloud and John Townsend to be helpful:
12 Christian Beliefs that Can Drive You Crazy
Changes that Heal
Boundaries (especially good for teaching how to deal with those women now)
I've put a lot out there --please feel free to follow up.