Hi, Mrmawker,
All I can say is that I went through a period kind of similar to what you’re going through - when I was in high school (only a year or so back), I experienced a crisis of faith and a subsequent fall into moral depravity. I started cursing very frequently, looked at inappropriate material on the internet, and many other things. I did this for a rather long time, and all the while continued to receive Communion, went to Confession occasionally and omitted sins, and even served at the altar often. Looking back on it now, my hypocrisy and sinfulness were astounding in my eyes. But finally, through what I think was the influence of the Holy Spirit and the model behavior of my best friend (among many other variables), I turned and frankly faced my sinful life, went to confession, and had a VERY long talk with my pastor…I essentially admitted all of my sins that I could remember from the past months, and we talked about them, and then he gave me absolution. And let me tell you, the feeling of forgiveness and relief was astounding when he did so - I felt washed clean and fresh, ready to start a new life renewed in my faith. I was no longer presenting a facade of devotion and faithfulness to God to the people around me - I could start anew and really live my life as I should, and in doing so, actually be the person that I had pretended to be before.
One problem that I faced after this was the fact that my previous lifestyle had become habitual, and so to my everlasting shame, I fell back into sin shortly after my confession. However, with the help of my priest and the indirect influence of my best friend and another of my friends, I managed to get back on my feet, go to confession again, and wash away my sins. It was VERY painful confessing the same sin of looking at pornography and the like, especially after I had made a promise to stop it, but after I confessed it, I felt better again. And ever since then, I have avoided all of that completely. The Sacrament of Confession is a truly blessed gift to us.
To be sure, I still commit many sins, and I confess them - such as pride, envy, anger, uncharitable or licentious thoughts, etc. - but all of those require a great deal of time to do away with, and not all of them are able to be completely discarded. They are part of what make us human, and I think it is impossible to completely do away with them. What matters is that you work your very hardest to stop committing them so often, and try to model your life after that of Christ. I of course cannot claim that I do the best job of this - no one can - but I think that I sincerely try, and in many ways succeed. You can’t expect to be perfect - only God is perfect - but striving to be perfect and to be a good person is the next best thing. As Christ said, “So be perfect, as your heavenly Father is perfect.” While you may not be able to be perfect, try your very hardest to, and in the meantime, go to confession when you fail to live up to the model of Christ and resolve firmly and sincerely to try better next time. Prayer helps immensely, as I found out when I was going through my trial.
As previous posters said, do not think of yourself as a horrible person. You are good at heart, but you are human, and humans are susceptible to temptation, so do not think that yours is a special case of “badness”. Living a holy life is the best armor against immorality and sin, and strengthens you in time of temptation. Hold on to your faith in God and Christ, and specifically remember that, as CatholicZ09 said, anything is possible with God. Go to confession, confess your sins, and if you can, have a good, long, and very frank talk with the priest - I’ve found that last part to be a great help. Once you find it within yourself to admit your sins to the priest and to God, things get easier from there.
I hope that wasn’t too disjointed, and I hope I helped ease your mind in some way. May you find peace within yourself!