The sin I'm talking about today is not a really bad sin but it's something that's against God. I try not to go against it, but I kept failing. What do I do? I hope I don't get the wrong responses of evil or from those who think they're better than me. Thanks but I want help.

I confessed it to God and prayed but it doesn't seem to help. I feel guilty and punished.
When I've done things like this in the past it was because somewhere in my life I was allowing particular temptations in. In our weak areas these temptations become irresistible if we don't dispose of them.
This is very different from any attempt to dispose of our Sin Nature. We have poisoned spiritual natures that we will not be able to dispose of until the resurrection. God expects us not to exterminate our poisoned spiritual nature, but to overcome its inclination to cooperate with it, to do wrong things.
For example, many of us have weaknesses towards things that God made to be good, but became warped through our Sin Nature. Many of us--perhaps most of us, have had to deal with Sexual Lusts. God gives us spouses, but our Sin Nature is tempted to want more.
In this case, we need to discipline ourselves to wear that ring, to avoid compromising situations, to avoid pornography, if possible (it is everywhere today). If we stay focused on our family, and on the wealth that exists within our own personal domain, we won't be tempted to look over in the neighbor's yard.
The same thing would apply to the perversion of our desire to be productive and to be successful. Our Sin Nature is wayward, and tends towards coveting more and more, even at the expense of others. In this case, we need to stay focused on our immediate needs, and to learn gratitude for what we have. There is no problem wanting to be successful. The problem comes when we begin to sacrifice others to be successful.
Much of this is simply the discipline of learning to avoid the pitfalls that tempt us. Once we allow those temptations to live nearby, we eventually capitulate to them. So learn to know what attacks your weaknesses, and avoid tempting situations like the plague! Good luck. :)
It really helps to remember to stay focused on Christ himself, and to learn to appreciate the richness of his spiritual love. When we realize that all virtue comes from him, we want to stay focused on that, to demonstrate it, and thus to please him. There will be no room for carnal desires.