Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, thank you for your question.
We really commend your sincere repentance and implore Allah Almighty to accept it and purify your heart. We, also, urge you to keep steadfast on that way and do as many good deeds as you can to expiate your sins.
As for your request to be punished by a Muslim Caliph, that is not possible in the Islamic world now. So, keep your sins top secrets and ask Allah Almighty for forgiveness; He will surely accept your repentance as long as you are sincere and will never return to such heinous sins again.
In response to the question you raised, the European Council for Fatwa and Research (ECFR) issued the following fatwa:
We commend your enthusiasm to return to the Straight Path and we pray that Allah Almighty accepts your repentance which is, Allah willing, sufficient to cleanse you from your sins. Make a resolution not to return to your old ways and Allah will help you to succeed and prosper.
However, the punishment is not an obligation upon you and it is enough for you to conceal yourself with the cover offered to you by Allah. So, do not talk to anyone about your sins and remain determined to abide by your repentance and return to Allah Almighty.
Allah Almighty knows best.