How can I make up for my transgressions against G-d

I always have the right intention, but throughout my life I struggle with the same sins. I have done unspeakable things such as ask for forgiveness for missing or not observing his law, but a few minutes later somehow rationalize it and commit the wrong doing again I then feel a sense of disgust and dread after. My soul knows what it wants, but somehow I always find a way to rationalize my decision as okay or just don’t think bout it and commit it. Does anybody know how I can be more religiously and generally more disciplined? How can I make up for what I have done in the past to G-d?