Without wanting to be offensive, OP, you sound arrogant. You're demanding God to do something, as is you deserve it. What you should get from God is not for you to decide, and what you deserve is not for you to judge. About a year ago I was struggling with depression and in my suffering I turned again everything: against my loved ones, against myself and against God and reality itself. It only caused more pain. And just in case, no, the Devil does not own your soul, and one single act does not necessarily condemn you.
Going back to the original point, here are some prayers that may help you. I know they do help me a lot, and are the ones I tend to use when I feel further away from God:
I Confess to You:
I confess to almighty God, and to you, my brothers and sisters, that I have sinned through my own fault, in my thoughts and in my words, in what I have done, and in what I have failed to do; and I ask blessed Mary, ever virgin, all the angels and saints, and you, my brothers and sisters, to pray for me to the Lord our God. Amen
Act of Contrition
O my God, I am heartily sorry for having offended Thee, and I detest all my sins, because I dread the loss of Heaven and the pains of Hell, but most of all because they offend Thee, my God, Who art all-good and deserving of all my love. I firmly resolve, with the help of Thy grace to confess my sins, to do penance and to amend my life. Amen.
Litany of humility
Have a link: ewtn.com/Devotionals/prayers/humility.htm
Pray them in that order, pray them like you mean it, chewing every word. It can be painful, but do it. Afterwards, proceed to your regular prayer (Pater Noster, Ave Maria, Signum Crucis, whatever you like to pray). While praying, try to contemplate your failings, and do it without self-pity nor self-judgement. No crap like "I'm so terrible, I can't do anything blah blah blah" or "I'm filth, I deserve death, I blah blah blah".
Try doing that. Won't even take you five minutes. Do it with a clean mind, without expecting something from it (an expectation is a demand; don't go around demanding stuff from the rest of reality, it owes you nothing). Hopefully it'll help, it certainly won't hurt.