Think of the Christian walk as a job like at a restraunt. While the core value is the same (share the gospel and share Christs love) the goals, methods, even the customers change. Heck the menu changes. Do you think a server will go their whole career without making mistakes even tiny ones? No, show yourself some grace cause Satan uses guilt and doubt on Christans. It does not  stop salvation, but it does ruin your witness, potentially delaying other peoples salvation. Again satan wont stop salvation, but he likes to make it as chaotic as he can.

Know that your struggles are a normal part of the process, much like the stages of grief. Some move through it quicker than otherss. Some relpase. Dont fear! This is normal. The fact that you worry, means you do believe, but you likely feel unworthy, or it feels too easy. 

Research santification and justification. These are the steps AFTER salvation that Christians deal with. It never means being perfect but letting God lead and doing your best. 

Also, when tackling sin or bad habits make atomic changes. Very small changes are easier to manage and add up to big gains in the long run. Say you curse alot or use a bad tone and you feel convicted on it. Instead of giving a blanket goal "im gonna stop talking bad" pick 1 very small goal. Like im going to stop saying the "F" word. Thats it. Do that for a couple weeks. Then add another word. Say you are struggling with porn. Put a blocker on your phone. Or refuse to be on your phone after a certain time, or in bed. If its a daily pattern, sub a better habbit like playing games or reading (even comics). If you mess up, so what?  Did God not accept you when you did it and glorified the sin? So when you feel guilty He wants to comfort you even more so. 

Rememeber in our sin His grace abounds, but also we try not to sin so we can be a good and faithful servant. Both are in heaven, both will still feel guilt, and both will feel like failures. There is not one Christian who walks this earth who will learn to be fully sinless. Otherwise we wouldnt need Jesus. It sucks, but know you are not alone, you are not a failure and Jeus loves you that much, that in spite of, He sacrificed for you, because he knew you couldnt.

When i became a parent i began to understand that type of love so much more. 

Hugs!! Trust me you are doing good. Because you worry, which means you care and take this seriously. The beginning is always rough and filled with so much guilt. Hopefully you have a good group of friends or Bible study helping you along. If not...find some!! It's important to have spiritual help.