I think many people would ask God to bless themselves, but is it a sin to seek God’s punishment and pray for your soul to be tormented because you think you do not really deserve to be with God in Heaven?
You may say: “Lord! I do not deserve to enter the Kingdom of Heaven, because I have disobeyed you and not worthy enough to sit by you in your kingdom. Damn me instead! I wish to go to Hell, because that’s the place where I deserve and desire.”
Sounds like you might have a problem with depression. I went through that myself. Once I actually wrote the Archbishop and asked to be excommunicated from the church. He didn’t do it. Why? Because there was nothing in me that deserved it. It was my depression talking. So, God won’t condemn you to hell just because you feel undeserving of his love and forgiveness. God sees you for where you are in your life, and loves you. He wants you to accept his love and grace. Well, forgiveness as well. It all comes together. Remember that Jesus suffered greatly for your salvation. He did it because of his love for you. He loves you enough to suffer everything for you. He loves you and is reaching out for you. Turn to him, and let him lead you to where he wants you to be.
Also, check with a doctor. Like I said, you might be depressed. There is help for that as well.
I don’t really know what to say to you in terms of doctrine. What I can tell you is that God loves you. Protestants will tell you that he does it even though we’re miserable worms in the dirt, but I don’t know about all that. I think that if God, omniscient and perfect as he is, can look at us in all of our sin and still see us as worth saving, then maybe we’re worth something after all. Certainly we must be worth something to him, if he calls us his children.
I don’t know whether you deserve hell. I don’t know whether I do. But what I do know is that God wants you to go to heaven, and that if I do make it up there to be with him, heaven will be an even better place if you’re there with me, too. So that’s at least two people who want to see you, right?
Please, if these thoughts persist, speak to a priest or a psychologist. If those aren’t available, speak to someone else who you trust. Depression can be a very difficult cross to bear, and keeping it to yourself doesn’t make it go away.
None of us deserve heaven. Salvation is a free and unmerited gift of God through the work of Jesus Christ and the power of the Holy Spirit. No sin is greater than God’s mercy, but you do have to accept the mercy. So, you can reject the gift-- but the question at hand seems to stem from either a serious ignorance of God’s mercy or possibly a mental illness. God would see into one’s heart on the matter and He can judge if one is rejecting His mercy from a right state of mind or not. I would say to ask God to damn you is definitely a sin, but if it is done without full knowledge (which could be the case) then it is not a mortal sin.
By the way, God already knows we are sinners and don’t obey Him. Even the just man falls seven times a day. Thankfully, we have the Sacraments which are fonts of God’s purifying grace.