I have a seemingly perfect life, but still I'm absolutely miserable.
What do you think is making you miserable?
I'm missing the feeling of being satisfied with myself
If you are not satisfied with your life, then that means something needs to change. Try to get some ideas from someone else about what to do.
Are you saying to me that I'm being too critical on myself?
You could be being too critical. But I can't tell you how to feel. Make a change somewhere and see if you can feel satisfied with yourself.