I'm glad you're going to talk about it with your therapist. Self-esteem is a ridiculously hard thing to gain and even then it fluctuates a lot. Some days I'm okay while some days I look at myself and just want to cry. There most definitely is a point in trying though because being positive to yourself is an amazing thing. To know that you are worth it is something that really brings much more into perspective.

There are lot of techniques to help with this sort of thing (and a whole part of the forum dedicated to this issue) but no one besides yourself can make the change towards stopping negative thoughts and turning them into positive things. Something interesting that you might want to try is sending out some text messages to your friends and family. Ask them to share some of your good traits and send them some of theirs. It is often harder to think objectively about yourself especially when you're feeling so crappy

Stay strong!