"Be kind to yourself. Stop telling yourself that whatever you are struggling with "should" be easy. If something is hard for you, it is hard for you. There are probably Reasons, though those may just be how you are wired. Acknowledge these things. When you finish something hard, be proud! Celebrate a little.
And really, just stop saying "should" to yourself about your thoughts and feelings in any context. You feel how you feel. The things in your head are the things in your head. You can't change either directly through sheer force of will. You can only change what you do. Stop beating yourself up for who and what you are right now–it isn't productive. Focus on moving forward."