I feel cheap and selfish if I dedicate myself to something else than fighting for justice. I can’t dedicate to anything else and it's amazing but totally awful both at once and I'm getting worn out. Is there some ways I can not feel this?

Sometimes as humans we behave in ways that we thing are ideal. Living our lives for a cause is noble--however, having a balanced approach is the most healthy. Imagine, if we only ate french fries everyday, because that's what we loved. Well, just think of all of the other nutrients that we would be missing from our diet. The same with living for one cause--yes, it is commendable, but it is not an all or nothing agenda. You can enjoy time with family--that is important too; exercise--that is important as well. Sometimes when we find ourselves acting out in the extremes (all or nothing approach), it could be that we are using that behavior to not have to deal with other things. It becomes where we go to "hide" so that we don't have to face other issues.