Hey there "CTOAN" (Maybe a name for you? LOL!)
I know I'm late to the party here. First, I want to encourage you to hold fast to God through the working of the Holy Spirit. He is, indeed, already at work in you. You wouldn't have come to Christ in the first place if this was not true.
Habits/behaviors/desires are not easily changed. There is a difference between 'Justification' (forgiveness of sin through the life,death, and ressurection of Christ) and 'Sancitifcation' (Christ, through the Holy Spirit, continuing to work in us and bring about change). That's a very brief, unofficial, take on it
So, while you are 'Justified' (declared righteous through the working of Christ), there is still work
to do if that makes sense.
Having said that, there's a bit of 'brain science' also involved. Areas of the human brain respond to cues in our environment that can motivate certain behavior. If I smell a good steak, cut into it and it's a perfect mid-rare, add some onion and mushrooms, then I'm all for it!

But why? Well, my brain has "learned" (in a sense) that steak=pleasure. There are neurotransmitters that are released when I see/smell/taste steak that is translated as "man, this is good". On the other hand, different chemicals we take into our body (alcohol, mj, other substances) brings about the same response, because we've leared to associate the substance with 'pleasure'. In essence it serves a purpose for us (stress and anxiety relief, and so on).
So how do we change that? In a sense we learn to "reprogram" the brain to recognize what is naturally rewarding and pleasurable. Steak instead of drink, going for a walk, eating well, exercise, play with the dog (if you have one)
While at the same time,
and more importantly, continjuing in prayer, bible reading, communicating your concerns to God - 1 Peter 5:7 tells us "cast all your anxieties (worries, cares) on [God] because he cares for you"
Finally, seek out Godly men in your church/community, perhaps Pastoral counselling to help maintain the changes you want to make
I wish you well in your walk with Christ. Rest assured, He is with you for the long haul