Self-doubt, self-hatred. You can reflect on the Preciousness of the Human Birth, that is one way to not feel so guilty for being a human being. Another thing you can try to do is learn how to give more. Be more generous in your life. It is very difficult to feel guilty when you are being generous. So do more generous actions and reflect on your generous actions. Then a lot of this type of guilt will tend to pass away because you realize you are at least doing something useful in the world and you don't have to feel guilty by doing something useful. So do more generous actions if you feel guilty, then perhaps that guilt will pass away.
Many people feel guilty if they are living a selfish life. So investigate into your lifestyle and see what you can do to make it more skillful. The more you develop the Paramis of Morality and Generosity, do more good Kamma and reflect on your good Kamma, the less guilty you will to feel.
Sometimes guilt arises because we are not doing enough, or we haven't enough courage to do what we feel we could do. So finding good things to do in small ways may give us a bit of momentum and feel better about ourselves. It is also helpful to look at our past and if we don't like some things we did, we can try to resolve these, by learning how to forgive ourselves. Forgiveness is very helpful for overcoming guilt.
If you tend to be an idealistic meditator, this can often result in feeling guilty. So investigate to see whether you have a lot of idealism and you're not able to live up to those ideals. Then, if this is the cause for feeling guilty, you can use the various techniques to learn have more compassion for ourselves by accepting our present limitations and gently expanding them.
A human being who is generous and trying to develop themselves can do a lot of wonderful things in the world. So we don't have to feel guilty for being alive if we are trying to develop ourselves.